Pith. sign in

REVIEW 3 major objections 4 minor 85 references

Mitigating Singlet Exciton Back-Transfer using 2D Spacer Layers for Perovskite-Sensitised Upconversion

T0 review · 3 major / 4 minor · reviewed 2026-08-15 · deepseek-v4-flash

Challenge this review Re-run · record.json Download PDF Read on arXiv ↗ Review JSON

Pith's one-line read Inserting a thin 2D perovskite layer between a 3D perovskite sensitiser and rubrene suppresses singlet back-transfer and improves low-light upconversion.

desk verdict Useful empirical demonstration that a thin 2D perovskite spacer improves low-power upconversion and 30-minute stability, but the claimed FRET back-transfer mechanism is underdetermined. read the letter →

arxiv 2505.05801 v1 pith:7UTHXQVU submitted 2025-05-09 cond-mat.mtrl-sci physics.app-ph

Nicholas P. Sloane , Damon M. de Clercq , Md Arafat Mahmud , Jianghui Zheng , Adrian Mena , Michael P. Nielsen , Anita W.Y. Ho-Baillie , Christopher G. Bailey
show 2 more authors
Timothy W. Schmidt Dane R. McCamey
This is my paper · ORCID
classification cond-mat.mtrl-sciphysics.app-ph
keywords photonupconversiontriplet-tripletannihilationsingletback-transferFörsterresonanceenergytransfer2Dperovskitespacerrubreneemittersolid-state
verification ladder T0 review T1 audit T2 compute T3 formal

The pith

A machine-rendered reading of the paper's core claim, the machinery that carries it, and where it could break.

The reading

The paper tries to establish that a thin two-dimensional perovskite spacer layer placed between a bulk perovskite sensitiser and a rubrene emitter can reduce a major loss pathway in triplet-triplet annihilation photon upconversion: the back-transfer of upconverted singlet excitons into the sensitiser. It matters because upconversion devices that work at sub-solar light intensities could benefit photovoltaics, photocatalysis, and imaging, but parasitic back-transfer has limited perovskite-sensitised systems. The authors show that a thin PEA2PbI4 layer lowers the intensity threshold for efficient upconversion and gives more stable upconverted emission, at the cost of lower absolute intensity when the spacer is thicker. The central trade-off is between suppressing near-field energy transfer, which improves with distance as $1/r^6$, and maintaining charge transfer that creates triplet excitons in the emitter.

What carries the argument

The central object is the two-dimensional Ruddlesden–Popper perovskite PEA2PbI4, formed by spin-coating phenethylammonium iodide onto the bulk perovskite surface. It plays two roles: a passivation layer that lengthens the bulk perovskite photoluminescence lifetime, and a spacer that increases the distance between the rubrene singlet excitons and the strongly absorbing sensitiser, weakening Förster resonance energy transfer back-transfer, which scales as $1/r^6$. The argument is carried by this distance dependence combined with lifetime measurements of the perovskite emission: adding rubrene shortens the P1 and P4 lifetimes relative to their neat films, and the P1/Rub trilayer lives longer than P4/Rub, which the authors attribute to stronger FRET-mediated singlet injection through the thinner spacer. Charge transport through the spacer is thought to proceed via direct transfer, defect-state hopping, or tunnelling, and this is what limits thicker spacers.

What would settle it

Directly measure the rubrene singlet population and lifetime with and without the spacer: excite rubrene singlets selectively and record time-resolved rubrene fluorescence or transient absorption while varying spacer thickness. If the P1/Rub trilayer shows no longer singlet lifetime or no reduced quenching relative to the bilayer, the back-transfer-mitigation mechanism would be refuted even if the relative efficiency trend remains.

Watch

Extended reading notes

Core claim

The central claim is that a PEA2PbI4 spacer grown from a 1 mg/mL PEAI treatment (P1/Rub) reduces singlet exciton back-transfer from rubrene:DBP to the 3D perovskite sensitiser by increasing the spatial separation, and that this is what makes the trilayer outperform the Control/Rub bilayer at excitation densities below about 100 mW/cm2. In support, the P1/Rub sample has a lower upconversion threshold intensity ($I_{th}=117$ mW/cm2 versus 250 mW/cm2), a higher relative upconversion efficiency at low power, and retains about 65% of its maximum upconverted emission after 30 minutes, compared to about 40% for the control. The same data show a clear trade-off: thicker spacers (P4, P8) progressively reduce triplet sensitisation and absolute upconversion intensity, and magneto-photoluminescence indicates triplet-charge annihilation is present in all working samples.

Load-bearing premise

The paper's central mechanism rests on reading changes in perovskite photoluminescence lifetimes as evidence of singlet back-transfer from rubrene, but it reports no direct measurement of that energy-transfer step; if the lifetime assignments are wrong, the mechanism loses its support.

Editorial extensions

If this is right

  • At sub-solar excitation densities (below roughly 100 mW/cm2), the P1/Rub trilayer converts more of the absorbed light into upconverted photons than the Control/Rub bilayer, making perovskite-sensitised upconversion more relevant for solar-powered applications.
  • The threshold for entering the efficient linear TTA regime drops from about 250 mW/cm2 to 117 mW/cm2, meaning the device can operate efficiently at much lower illumination.
  • Thicker spacers (P4, P8) sacrifice absolute upconversion intensity because charge transfer and triplet formation in rubrene are increasingly hindered, so spacer thickness must be tuned to balance FRET suppression against triplet sensitisation.
  • Trilayers retain 65% (P1/Rub) and 85% (P4/Rub) of their maximum upconverted emission after 30 minutes, versus about 40% for the bilayer, indicating improved operational stability.
  • Magneto-photoluminescence shows that triplet-charge annihilation, not only TTA, affects all working samples, so future improvements must manage charge imbalance in the emitter layer as well as back-transfer.

Reading between the lines

Editorial extensions of the paper, not claims the author makes directly.

  • By the same $1/r^6$ argument, other wide-bandgap, hole-transporting interlayers of comparable thickness should also reduce singlet back-transfer; the paper's mechanism predicts a monotonic relation between spacer thickness and low-power efficiency until charge transfer fails, which could be tested directly.
  • If the back-transfer mechanism is correct, moving rubrene emission further from the sensitiser absorption edge through chemical substitution or host choice would complement the spacer and could push the efficient regime below 50 mW/cm2 without sacrificing triplet injection.
  • The paper's lifetime evidence is indirect; a direct transient-absorption measurement of rubrene singlet population as a function of spacer thickness would turn the inferred FRET suppression into a quantitative rate, and could separate passivation effects from distance effects.
  • Quasi-2D or vertically oriented 2D perovskites, which the authors mention as future directions, would test whether the same back-transfer suppression survives when charge transport through the spacer is improved.
Share X Bluesky LinkedIn Reddit HN

Signed reviews

No signed human review yet.

Editorial analysis

A structured set of objections, weighed in public.

Desk editor's note, referee report, and a circularity audit.

Referee Report

3 major / 4 minor

Summary. The manuscript investigates the use of a 2D PEA2PbI4 spacer layer between a bulk 3D perovskite sensitiser (Br17) and a rubrene:DBP emitter for triplet-triplet annihilation photon upconversion. Four systems are compared: a Control/Rub bilayer and three trilayers with increasing PEAI treatment thickness (P1/Rub, P4/Rub, P8/Rub). The authors report that the P1/Rub trilayer exhibits a lower threshold intensity (Ith = 117 mW/cm2 vs. 250 mW/cm2 for Control/Rub), higher relative upconversion efficiency at sub-solar excitation densities, and improved stability of the upconverted photoluminescence over 30 minutes. They attribute the low-power enhancement primarily to reduced singlet exciton back-transfer from rubrene to the perovskite via FRET, owing to the increased physical separation introduced by the 2D spacer, while acknowledging a trade-off with reduced triplet sensitisation through the thicker spacer layers.

Significance. If the mechanistic claim were firmly established, this work would offer a useful and simple design rule for perovskite-sensitised upconversion: inserting a thin 2D perovskite spacer can suppress parasitic singlet FRET back-transfer while retaining triplet injection, with practical relevance at sub-solar fluences. The paper has clear strengths: the empirical trends are supported by multiple measurement types, the boxplot statistics cover multiple films and spots, and the stability data show a consistent improvement in the trilayer samples. The work also explicitly discusses the trade-off between passivation, charge transport, and FRET suppression, which is a step toward rational device design. However, the central mechanistic attribution to reduced back-transfer is indirect, resting on lifetime comparisons and power-law fits without direct FRET rate measurements or control experiments that isolate the distance effect from surface passivation.

major comments (3)
  1. [Results and Discussion, Table 1 and Figs. 3a-b, 4d] The central claim that the 2D PEA2PbI4 spacer mitigates singlet back-transfer via the 1/r^6 FRET distance dependence is not uniquely supported by the data. The neat-perovskite average lifetime rises from 31.0 ns (Control) to 61.6 ns (P1) and 91.7 ns (P4) after PEAI treatment (Table 1), indicating strong surface passivation that alone raises the triplet supply to rubrene at low fluence. The thickness series P1/P4/P8 cannot separate the proposed distance effect from simultaneous changes in passivation, PEAI concentration, and charge-transport barrier. In addition, the lifetime data are used both to infer FRET-mediated injection (P1/Rub longer-lived than P4/Rub when rubrene is added) and to explain the same lifetime ordering, which is an interpretive loop. A direct measurement of the FRET rate (e.g., transient absorption of rubrene singlets) or a control with an inert spacer of matched thickness is needed before the mechanism in the title can be regarded as established.
  2. [Fig. 4a-c and accompanying text] The power-dependence data for P1/Rub show slopes k = 1.03 at low powers and k = 0.56 at high powers, not the canonical quadratic-to-linear (2 to 1) TTA crossover. Labeling Ith = 117 mW/cm2 as the TTA threshold and interpreting the lower Ith as evidence for more efficient TTA is therefore not justified. The authors rationalize the halved slope via TCA, but no quantitative model or uncertainty estimates for the fitted k and Ith values are provided, and the MPL fits (Fig. 3c) are explicitly 'to guide the eye.' The lower crossover could equally arise from a different balance of injection, passivation, and TCA rather than from reduced back-transfer.
  3. [Conclusion / Fig. 4d] The manuscript correctly identifies a trade-off between reduced back-transfer and reduced triplet sensitisation, but it does not quantify this trade-off. Since the high-power upconversion intensity of P1/Rub is lower than that of Control/Rub (Fig. 2b), the improved low-power relative efficiency in Fig. 4d could be dominated by enhanced carrier survival (passivation) rather than by a distance-dependent suppression of FRET. Without a rate-equation analysis that includes the measured lifetimes and an independent estimate of the FRET radius, the relative weights of the two effects remain unknown, so the central conclusion should be softened or supported by additional experiments.
minor comments (4)
  1. [Title page] The title contains a spacing typo: 'Back-T ransfer' should read 'Back-Transfer'.
  2. [Results and Discussion, Fig. 4d paragraph] The sentence 'the P4/Rub trilayer is shows a low relative upconversion efficiency' should read 'the P4/Rub trilayer shows a low relative upconversion efficiency'.
  3. [Fig. 2 caption] The caption for Fig. 2b does not state the excitation wavelength and power density used for the boxplot; the main text mentions approximately 4 W/cm^2, but the caption should include this information for completeness.
  4. [Supporting Note 4] The non-Lorentzian fit function f(B) = A B^2/(|B| + sigma)^2 is stated to be approximate and 'to guide the eye', but the resulting A and sigma values are not reported anywhere, nor are goodness-of-fit measures; adding these values in the Supporting Information would strengthen the MPL discussion.

Circularity Check

0 steps flagged · score 0.0 of 10

No significant circularity: the reported efficiency, threshold, and stability results are measured outputs, and the FRET back-transfer mechanism is presented as an explicit interpretation rather than a conclusion forced by construction.

full rationale

The paper's central empirical claims—higher relative upconversion efficiency at low excitation power, lower fitted Ith for P1/Rub, and improved stability—are directly measured quantities, not parameters fitted to the data and then renamed as predictions. The power-law slopes and Ith values in Figure 4a-c are fits to the excitation-dependence data, but the paper does not claim to predict them from the spacer model; it uses them as empirical evidence. The FRET back-transfer mechanism is inferred from the standard 1/r^6 distance dependence and from lifetime differences in Table 1, yet the authors explicitly flag the inference as an attribution rather than a derivation: they say the P1/Rub lifetime increase 'is attributed to' FRET-mediated injection, offer 'one rationalisation' for the non-canonical power slopes, and state that 'care must be taken in assigning changes in PL lifetimes for these complex systems.' This is an interpretive, underdetermined mechanistic claim, not a circular one. The self-citations (e.g., refs 13, 19, 21, 50, 53, 73, 75, 76) support background concepts such as TTA utility, band alignment, and 2D perovskite magneto-optical behaviour, but none is the sole load-bearing justification for the main result; external references independently establish the charge-transfer mechanism, the spacer-layer strategy, and 2D perovskite passivation. No equation in the paper defines a derived quantity in terms of the claimed conclusion, and no fitted parameter is relabelled as a prediction. The absence of direct FRET or singlet back-transfer measurements is an evidence-strength limitation, appropriately raised by the authors, but it does not make the derivation circular.

Assumptions & free parameters 4 free parameters · 4 assumptions · 0 invented entities

The central claims rest on fitted exponents and thresholds, on standard physics assumptions such as FRET scaling and TCA models, and on the assumed formation and thickness of the PEA2PbI4 spacer. No new physical entities are introduced; the 2D perovskite is a fabricated material rather than a postulated entity.

free parameters (4)
  • Power-law exponents k (Control/Rub, P1/Rub, P4/Rub) = 1.94, 0.75; 1.03, 0.56; 1.01
    Fitted to log-log excitation dependence data; the differences in slopes drive the relative efficiency comparison in Figure 4d.
  • Threshold intensity Ith = 250 mW/cm2 (Control), 117 mW/cm2 (P1/Rub)
    Crossover extracted from piecewise linear fits; central to the claim of more efficient TTA at low powers.
  • Triexponential PL lifetimes and average tau = Control 31.0 ns; P1 61.6; P4 91.7; P8 13.2; with rubrene 31.8, 47.1, 45.7, 25.5 ns
    Used to infer passivation and FRET-mediated injection; no uncertainties are reported.
  • MPL non-Lorentzian fit parameters A and sigma = Not tabulated
    Used for guide-eye fits to magneto-photoluminescence curves; no error bars are provided.
assumptions (4)
  • domain assumption FRET back-transfer scales as 1/r^6 with distance.
    Used to argue that a thicker spacer layer reduces singlet back-transfer into the perovskite sensitiser.
  • domain assumption The 2D spacer layer is PEA2PbI4 and its thickness scales with PEAI concentration.
    Based on XRD/SEM and prior calibration from reference 58; thickness enters the FRET distance argument.
  • domain assumption A monotonic increase in MPL indicates triplet-charge annihilation (TCA) dominance.
    Adopted from Merrifield theory; used to interpret the presence of excess charges in the rubrene layer.
  • domain assumption Electrons and holes traverse the 2D spacer via tunnelling or hopping through defect states.
    Proposed to explain why upconversion still occurs in trilayers despite the large bandgap of PEA2PbI4; not directly measured.

how reviews work

0 comments
Cite this review

Pith. "Pith review of Mitigating Singlet Exciton Back-Transfer using 2D Spacer Layers for Perovskite-Sensitised Upconversion." pith.science (2026). https://pith.science/paper/7UTHXQVU

@misc{pith2026250505801,
  author       = {Pith},
  title        = {Pith review of: Mitigating Singlet Exciton Back-Transfer using 2D Spacer Layers for Perovskite-Sensitised Upconversion},
  year         = {2026},
  howpublished = {\url{https://pith.science/paper/7UTHXQVU}},
  note         = {Machine review of arXiv:2505.05801}
}
read the original abstract

Photon upconversion has potential applications in light-emitting diodes, photocatalysis, bio-imaging, microscopy, 3D printing, and photovoltaics. Bulk lead-halide perovskite films have emerged as promising sensitisers for solid-state photon upconversion via triplet-triplet annihilation due to their excellent optoelectronic properties. In this system, a perovskite sensitiser absorbs photons and subsequently generates triplet excitons in an adjacent emitter material, where triplet-triplet annihilation can occur allowing for the emission of higher energy photons. However, a major loss pathway in perovskite-sensitised upconversion is the back-transfer of singlet excitons from the emitter to the sensitiser via F\"orster Resonance Energy Transfer. In this investigation we introduce a 2D perovskite spacer layer between the bulk perovskite sensitiser and a rubrene emitter to mitigate back-transfer of singlet excitons from rubrene to the bulk perovskite sensitiser. This modification reveals the inherent balance between efficient triplet exciton transfer across the interface with a potential barrier versus the mitigation of near-field back-transfer by increasing the distance between the sensitiser and singlet excitons in the emitter. Notably, the introduction of this spacer layer enhances the relative upconversion efficiency at lower excitation power densities while also sustaining performance over extended timescales. This work represents significant progress toward the practical applications of perovskite-sensitised photon upconversion.

Figures

Figures reproduced from arXiv: 2505.05801 by the authors.

Figure 1
Figure 1. (a) Schematic of the upconversion process in a 3D perovskite/rubrene bilayer. [PITH_FULL_IMAGE:figures/full_fig_p005_1.png] view at source ↗
Figure 2
Figure 2. (a) Photoluminescence from the upconverting samples excited at [PITH_FULL_IMAGE:figures/full_fig_p008_2.png] view at source ↗
Figure 3
Figure 3. (a) Perovskite PL decay dynamics (> 725 nm) for the (a) neat perovskite and (b) upconverting samples, excited at 700 nm. The solid lines are triexponential fits with the parameters shown in (a) Table S1 and (b) S2. (c) MPL of the upconverted emission (λ < 650 nm) from the upconverting samples Control/Rub, P1/Rub, and P4/Rub. The solid lines are approximate fits of a non-Lorentzian function to guide the eye (see Supp… view at source ↗
Figures from the paper (1 more)
Figure 4
Figure 4. Figure 4: Excitation dependence of the upconverted emission ( [PITH_FULL_IMAGE:figures/full_fig_p014_4.png]

Discussion (0). Continue with ORCID to comment.

Reference graph

Works this paper leans on

85 extracted references · 78 canonical work pages

  1. [1]

    Upconversion nanoparticles in biological labeling, imaging, and therapy

    Wang, F.; Banerjee, D.; Liu, Y.; Chen, X.; Liu, X. Upconversion nanoparticles in biological labeling, imaging, and therapy . Analyst 2010, 135, 1839--1854

    2010

  2. [2]

    Highly Emissive Dye-Sensitized Upconversion Nanostructure for Dual-Photosensitizer Photodynamic Therapy and Bioimaging

    Xu, J.; Yang, P.; Sun, M.; Bi, H.; Liu, B.; Yang, D.; Gai, S.; He, F.; Lin, J. Highly Emissive Dye-Sensitized Upconversion Nanostructure for Dual-Photosensitizer Photodynamic Therapy and Bioimaging . ACS Nano 2017, 11, 4133--4144

    2017

  3. [3]

    J.; Chan, E

    Gargas, D. J.; Chan, E. M.; Ostrowski, A. D.; Aloni, S.; Altoe, M. V. P.; Barnard, E. S.; Sanii, B.; Urban, J. J.; Milliron, D. J.; Cohen, B. E.; Schuck, P. J. Engineering bright sub-10-nm upconverting nanocrystals for single-molecule imaging . Nature Nanotechnology 2014, 9, 300--305

    2014

  4. [4]

    A.; Xi, P.; Jin, D

    Liu, Y.; Lu, Y.; Yang, X.; Zheng, X.; Wen, S.; Wang, F.; Vidal, X.; Zhao, J.; Liu, D.; Zhou, Z.; Ma, C.; Zhou, J.; Piper, J. A.; Xi, P.; Jin, D. Amplified stimulated emission in upconversion nanoparticles for super-resolution nanoscopy . Nature 2017, 543, 229--233

    2017

  5. [5]

    S.; Blumhoff, J.; Harrington, J

    Khnayzer, R. S.; Blumhoff, J.; Harrington, J. A.; Haefele, A.; Deng, F.; Castellano, F. N. Upconversion-powered photoelectrochemistry . Chemical Communications 2011, 48, 209--211

    2011

  6. [6]

    D.; Pun, A

    Ravetz, B. D.; Pun, A. B.; Churchill, E. M.; Congreve, D. N.; Rovis, T.; Campos, L. M. Photoredox catalysis using infrared light via triplet fusion upconversion . Nature 2019, 565, 343--346

    work page 2019

  7. [7]

    N.; Schloemer, T

    Sanders, S. N.; Schloemer, T. H.; Gangishetty, M. K.; Anderson, D.; Seitz, M.; Gallegos, A. O.; Stokes, R. C.; Congreve, D. N. Triplet fusion upconversion nanocapsules for volumetric 3D printing . Nature 2022, 604, 474--478

    work page 2022

  8. [8]

    K.; Nunzi, J

    Pandey, A. K.; Nunzi, J. M. Rubrene/Fullerene Heterostructures with a Half-Gap Electroluminescence Threshold and Large Photovoltage . Advanced Materials 2007, 19, 3613--3617

    work page 2007

Show all 85 references
  1. [9]

    Determining the Origin of Half-bandgap-voltage Electroluminescence in Bifunctional Rubrene/C60 Devices

    Chen, Q.; Jia, W.; Chen, L.; Yuan, D.; Zou, Y.; Xiong, Z. Determining the Origin of Half-bandgap-voltage Electroluminescence in Bifunctional Rubrene/C60 Devices . Scientific Reports 2016, 6, 25331

    2016

  2. [10]

    Blue organic light-emitting diode with a turn-on voltage of 1.47 V

    Izawa, S.; Morimoto, M.; Fujimoto, K.; Banno, K.; Majima, Y.; Takahashi, M.; Naka, S.; Hiramoto, M. Blue organic light-emitting diode with a turn-on voltage of 1.47 V . Nature Communications 2023, 14, 5494

    2023

  3. [11]

    Y.; F \" u ckel, B.; MacQueen, R

    Cheng, Y. Y.; F \" u ckel, B.; MacQueen, R. W.; Khoury, T.; Clady, R. G. C. R.; Schulze, T. F.; Ekins-Daukes, N. J.; Crossley, M. J.; Stannowski, B.; Lips, K.; Schmidt, T. W. Improving the light-harvesting of amorphous silicon solar cells with photochemical upconversion . Ener...

    2012

  4. [12]

    F.; Schmidt, T

    Schulze, T. F.; Schmidt, T. W. Photochemical upconversion: present status and prospects for its application to solar energy conversion . Energy & Environmental Science 2015, 8, 103--125

    2015

  5. [13]

    Tayebjee, M. J. Y.; McCamey, D. R.; Schmidt, T. W. Beyond Shockley–Queisser: Molecular Approaches to High-Efficiency Photovoltaics . The Journal of Physical Chemistry Letters 2015, 6, 2367--2378

    2015

  6. [14]

    S.; Hudry, D.; Busko, D.; Turshatov, A.; Howard, I

    Richards, B. S.; Hudry, D.; Busko, D.; Turshatov, A.; Howard, I. A. Photon Upconversion for Photovoltaics and Photocatalysis: A Critical Review . Chemical Reviews 2021, 121, 9165--9195

    2021

  7. [15]

    Triplet–triplet annihilation mediated photon upconversion solar energy systems

    Naimovi c ius, L.; Bharmoria, P.; Moth-Poulsen, K. Triplet–triplet annihilation mediated photon upconversion solar energy systems . Materials Chemistry Frontiers 2023, 7, 2297--2315

    2023

  8. [16]

    N.; Castellano, F

    Singh-Rachford, T. N.; Castellano, F. N. Photon upconversion based on sensitized triplet–triplet annihilation . Coordination Chemistry Reviews 2010, 254, 2560--2573

    2010

  9. [17]

    W.; Castellano, F

    Schmidt, T. W.; Castellano, F. N. Photochemical Upconversion: The Primacy of Kinetics . The Journal of Physical Chemistry Letters 2014, 5, 4062--4072

    2014

  10. [18]

    S.; Pusch, A.; Nielsen, M

    Sharma, A. S.; Pusch, A.; Nielsen, M. P.; R \" o mer, U.; Tayebjee, M. J.; Rougieux, F. E.; Ekins-Daukes, N. J. Constraints imposed by the sparse solar photon flux on upconversion and hot carrier solar cells . Solar Energy 2022, 237, 44--51

    2022

  11. [19]

    M.; Schmidt, T

    Feng, J.; Alves, J.; de Clercq, D. M.; Schmidt, T. W. Photochemical Upconversion . Annual Review of Physical Chemistry 2023, 74, 145--168

    2023

  12. [20]

    A design of intermediate band solar cell for photon ratchet with multi-layer MoS _2 nanoribbons

    Chen, S.-F.; Wu, Y.-R. A design of intermediate band solar cell for photon ratchet with multi-layer MoS _2 nanoribbons . Applied Physics Letters 2017, 110

    2017

  13. [21]

    Y.; F \" u ckel, B.; Khoury, T.; Clady, R

    Cheng, Y. Y.; F \" u ckel, B.; Khoury, T.; Clady, R. G. C. R.; Tayebjee, M. J. Y.; Ekins-Daukes, N. J.; Crossley, M. J.; Schmidt, T. W. Kinetic Analysis of Photochemical Upconversion by Triplet-Triplet Annihilation: Beyond Any Spin Statistical Limit . The Journal of Physical C...

    2010

  14. [22]

    Pusch, A.; Ekins-Daukes, N. J. Voltage Matching, \' E tendue, and Ratchet Steps in Advanced-Concept Solar Cells . Physical Review Applied 2019, 12, 044055

    2019

  15. [23]

    Dexter, D. L. A Theory of Sensitized Luminescence in Solids . The Journal of Chemical Physics 1953, 21, 836--850

    1953

  16. [24]

    E.; Klein, N

    Nienhaus, L.; Correa-Baena, J.-P.; Wieghold, S.; Einzinger, M.; Lin, T.-A.; Shulenberger, K. E.; Klein, N. D.; Wu, M.; Bulovi \' c , V.; Buonassisi, T.; Baldo, M. A.; Bawendi, M. G. Triplet-Sensitization by Lead Halide Perovskite Thin Films for Near-Infrared-to-Visible Upconve...

    2019

  17. [25]

    S.; VanOrman, Z

    Wieghold, S.; Bieber, A. S.; VanOrman, Z. A.; Daley, L.; Leger, M.; Correa-Baena, J. P.; Nienhaus, L. Triplet Sensitization by Lead Halide Perovskite Thin Films for Efficient Solid-State Photon Upconversion at Subsolar Fluxes . Matter 2019, 1, 705--719

    2019

  18. [26]

    M.; Nienhaus, L

    Sullivan, C. M.; Nienhaus, L. Across the Interface: Understanding the Mechanism of Perovskite-Sensitized Triplet–Triplet Annihilation . ACS Applied Energy Materials 2025,

    2025

  19. [27]

    M.; Nichols, V

    Huang, Z.; Li, X.; Mahboub, M.; Hanson, K. M.; Nichols, V. M.; Le, H.; Tang, M. L.; Bardeen, C. J. Hybrid Molecule-Nanocrystal Photon Upconversion Across the Visible and Near-Infrared . Nano Letters 2015, 15, 5552--5557

    2015

  20. [28]

    N.; Wilson, M

    Wu, M.; Congreve, D. N.; Wilson, M. W. B.; Jean, J.; Geva, N.; Welborn, M.; Van Voorhis, T.; Bulovi \' c , V.; Bawendi, M. G.; Baldo, M. A. Solid-state infrared-to-visible upconversion sensitized by colloidal nanocrystals . Nature Photonics 2016, 10, 31--34

    2016

  21. [29]

    Triplet sensitization by perovskite nanocrystals for photon upconversion

    Mase, K.; Okumura, K.; Yanai, N.; Kimizuka, N. Triplet sensitization by perovskite nanocrystals for photon upconversion . Chemical Communications 2017, 53, 8261--8264

    2017

  22. [30]

    E.; Kamat, P

    Chakkamalayath, J.; Martin, L. E.; Kamat, P. V. Energy Cascade in Halide Perovskite-Multiple Chromophore Films: Direct versus Mediated Transfer . ACS Photonics 2024, 11, 1821--1831

    2024

  23. [31]

    Chakkamalayath, J.; Kamat, P. V. Demystifying Triplet–Triplet Annihilation Mechanism in the CsPbI _3 –Rubrene–DBP Upconversion System . Journal of the American Chemical Society 2024, 146, 18095--18103

    2024

  24. [32]

    M.; Nienhaus, L

    Sullivan, C. M.; Nienhaus, L. Recharging upconversion: revealing rubrene's replacement . Nanoscale 2022, 14, 17254--17261

    2022

  25. [33]

    M.; Nienhaus, L

    Sullivan, C. M.; Nienhaus, L. Turning on TTA: Tuning the Energy Landscape by Intermolecular Coupling . Chemistry of Materials 2024, 36, 417--424

    2024

  26. [34]

    M.; Szucs, A

    Sullivan, C. M.; Szucs, A. M.; Cantrell, A. P.; Shulenberger, K. E.; Siegrist, T.; Nienhaus, L. Which Flavor of 9,10-Bis(phenylethynyl)Anthracene is Best for Perovskite-Sensitized Triplet–Triplet Annihilation? Advanced Energy Materials 2024, 2404130

    2024

  27. [35]

    S.; VanOrman, Z

    Wieghold, S.; Bieber, A. S.; VanOrman, Z. A.; Nienhaus, L. Influence of Triplet Diffusion on Lead Halide Perovskite-Sensitized Solid-State Upconversion . The Journal of Physical Chemistry Letters 2019, 10, 3806--3811

    2019

  28. [36]

    Precharging Photon Upconversion: Interfacial Interactions in Solution-Processed Perovskite Upconversion Devices

    Wieghold, S.; Nienhaus, L. Precharging Photon Upconversion: Interfacial Interactions in Solution-Processed Perovskite Upconversion Devices . Journal of Physical Chemistry Letters 2020, 11, 601--607

    2020

  29. [37]

    S.; VanOrman, Z

    Wieghold, S.; Bieber, A. S.; VanOrman, Z. A.; Rodriguez, A.; Nienhaus, L. Is Disorder Beneficial in Perovskite-Sensitized Solid-State Upconversion? The Role of DBP Doping in Rubrene . The Journal of Physical Chemistry C 2020, 124, 18132--18140

    2020

  30. [38]

    S.; Lackner, J.; Nienhaus, K.; Nienhaus, G

    Wieghold, S.; Bieber, A. S.; Lackner, J.; Nienhaus, K.; Nienhaus, G. U.; Nienhaus, L. One-Step Fabrication of Perovskite-Based Upconversion Devices . ChemPhotoChem 2020, 4, 704--712

    2020

  31. [39]

    S.; VanOrman, Z

    Bieber, A. S.; VanOrman, Z. A.; Wieghold, S.; Nienhaus, L. Perovskite-sensitized upconversion bingo: Stoichiometry, composition, solvent, or temperature? The Journal of Chemical Physics 2020, 153, 084703

    2020

  32. [40]

    Prashanthan, K.; Naydenov, B.; Lips, K.; Unger, E.; MacQueen, R. W. Interdependence of photon upconversion performance and antisolvent processing in thin-film halide perovskite-sensitized triplet–triplet annihilators . The Journal of Chemical Physics 2020, 153, 164711

    2020

  33. [41]

    A.; Lackner, J.; Wieghold, S.; Nienhaus, K.; Nienhaus, G

    VanOrman, Z. A.; Lackner, J.; Wieghold, S.; Nienhaus, K.; Nienhaus, G. U.; Nienhaus, L. Efficiency of bulk perovskite-sensitized upconversion: Illuminating matters . Applied Physics Letters 2021, 118, 203903

    2021

  34. [42]

    S.; Vanorman, Z

    Bieber, A. S.; Vanorman, Z. A.; Drozdick, H. K.; Weiss, R.; Wieghold, S.; Nienhaus, L. Mixed halide bulk perovskite triplet sensitizers: Interplay between band alignment, mid-gap traps, and phonons . Journal of Chemical Physics 2021, 155, 234706

    2021

  35. [43]

    J.; Lin, T.; Perkinson, C

    Wang, L.; Yoo, J. J.; Lin, T.; Perkinson, C. F.; Lu, Y.; Baldo, M. A.; Bawendi, M. G. Interfacial Trap‐Assisted Triplet Generation in Lead Halide Perovskite Sensitized Solid‐State Upconversion . Advanced Materials 2021, 33, 2100854

    2021

  36. [44]

    R.; Bieber, A

    Conti, C. R.; Bieber, A. S.; VanOrman, Z. A.; Moller, G.; Wieghold, S.; Schaller, R. D.; Strouse, G. F.; Nienhaus, L. Ultrafast Triplet Generation at the Lead Halide Perovskite/Rubrene Interface . ACS Energy Letters 2022, 2022, 617--623

    2022

  37. [45]

    Prashanthan, K.; Levine, I.; Musiienko, A.; Gutierrez-Partida, E.; Hempel, H.; Lips, K.; Unold, T.; Stolterfoht, M.; Dittrich, T.; MacQueen, R. W. Internal electric fields control triplet formation in halide perovskite-sensitized photon upconverters . iScience 2023, 26, 106365

    2023

  38. [46]

    M.; Bieber, A

    Sullivan, C. M.; Bieber, A. S.; Drozdick, H. K.; Moller, G.; Kuszynski, J. E.; VanOrman, Z. A.; Wieghold, S.; Strouse, G. F.; Nienhaus, L. Surface Doping Boosts Triplet Generation Yield in Perovskite‐Sensitized Upconversion . Advanced Optical Materials 2023, 11, 2201921

    2023

  39. [47]

    High efficiency red organic light-emitting devices using tetraphenyldibenzoperiflanthene-doped rubrene as an emitting layer

    Okumoto, K.; Kanno, H.; Hamada, Y.; Takahashi, H.; Shibata, K. High efficiency red organic light-emitting devices using tetraphenyldibenzoperiflanthene-doped rubrene as an emitting layer . Applied Physics Letters 2006, 89, 013502

    2006

  40. [48]

    G.; Sasaki, Y.; Wang, S.; Chekulaev, D.; Kimizuka, N.; Yanai, N.; Clark, J

    Bossanyi, D. G.; Sasaki, Y.; Wang, S.; Chekulaev, D.; Kimizuka, N.; Yanai, N.; Clark, J. In optimized rubrene-based nanoparticle blends for photon upconversion, singlet energy collection outcompetes triplet-pair separation, not singlet fission . Journal of Materials Chemistry ...

    2022

  41. [49]

    J.; L \" o per, P.; Niesen, B.; Ledinsky, M.; Haug, F

    De Wolf, S.; Holovsky, J.; Moon, S. J.; L \" o per, P.; Niesen, B.; Ledinsky, M.; Haug, F. J.; Yum, J. H.; Ballif, C. Organometallic halide perovskites: Sharp optical absorption edge and its relation to photovoltaic performance . Journal of Physical Chemistry Letters 2014, 5, ...

    2014

  42. [50]

    G.; Piana, G

    Bailey, C. G.; Piana, G. M.; Lagoudakis, P. G. High-Energy Optical Transitions and Optical Constants of CH _3 NH _3 PbI _3 Measured by Spectroscopic Ellipsometry and Spectrophotometry . The Journal of Physical Chemistry C 2019, 123, 28795--28801

    2019

  43. [51]

    S.; Savenije, T

    Ponseca, C. S.; Savenije, T. J.; Abdellah, M.; Zheng, K.; Yartsev, A.; Pascher, T.; Harlang, T.; Chabera, P.; Pullerits, T.; Stepanov, A.; Wolf, J. P.; Sundstr \" o m, V. Organometal halide perovskite solar cell materials rationalized: Ultrafast charge generation, high and mic...

    2014

  44. [52]

    E.; Wang, J

    Galkowski, K.; Mitioglu, A.; Miyata, A.; Plochocka, P.; Portugall, O.; Eperon, G. E.; Wang, J. T. W.; Stergiopoulos, T.; Stranks, S. D.; Snaith, H. J.; Nicholas, R. J. Determination of the exciton binding energy and effective masses for methylammonium and formamidinium lead tr...

    2016

  45. [53]

    Alves, J.; Feng, J.; Nienhaus, L.; Schmidt, T. W. Challenges, progress and prospects in solid state triplet fusion upconversion . Journal of Materials Chemistry C 2022, 10, 7783--7798

    2022

  46. [54]

    F.; Baldo, M

    Lin, T.-A.; Perkinson, C. F.; Baldo, M. A.; Lin, T.-a.; Baldo, M. A.; Perkinson, C. F. Strategies for High-Performance Solid-State Triplet–Triplet-Annihilation-Based Photon Upconversion . Advanced Materials 2020, 32, 1908175

    2020

  47. [55]

    O.; Pucurimay, L.; Zhou, Q.; Belliveau, E.; Ahmed, G

    Narayanan, P.; Hu, M.; Gallegos, A. O.; Pucurimay, L.; Zhou, Q.; Belliveau, E.; Ahmed, G. H.; Fern \' a ndez, S.; Michaels, W.; Murrietta, N.; Mutatu, V. E.; Feng, D.; Hamid, R.; Yap, K. M. K.; Schloemer, T. H.; Jaramillo, T. F.; Kats, M. A.; Congreve, D. N. Overcoming the Abs...

    2024 doi

  48. [56]

    Surface Passivation Using 2D Perovskites toward Efficient and Stable Perovskite Solar Cells

    Wu, G.; Liang, R.; Ge, M.; Sun, G.; Zhang, Y.; Xing, G. Surface Passivation Using 2D Perovskites toward Efficient and Stable Perovskite Solar Cells . Advanced Materials 2022, 34, 2105635

    2022

  49. [57]

    Y.; Domanski, K.; Correa-Baena, J

    Saliba, M.; Matsui, T.; Seo, J. Y.; Domanski, K.; Correa-Baena, J. P.; Nazeeruddin, M. K.; Zakeeruddin, S. M.; Tress, W.; Abate, A.; Hagfeldt, A.; Gr \" a tzel, M. Cesium-containing triple cation perovskite solar cells: improved stability, reproducibility and high efficiency ....

    2016

  50. [58]

    H.; Wang, L

    Chen, P.; Bai, Y.; Wang, S.; Lyu, M.; Yun, J. H.; Wang, L. In Situ Growth of 2D Perovskite Capping Layer for Stable and Efficient Perovskite Solar Cells . Advanced Functional Materials 2018, 28, 1706923

    2018

  51. [59]

    T.; Grancini, G.; Lee, Y.; Oveisi, E.; Ryu, J.; Almora, O.; Tschumi, M.; Schouwink, P

    Cho, K. T.; Grancini, G.; Lee, Y.; Oveisi, E.; Ryu, J.; Almora, O.; Tschumi, M.; Schouwink, P. A.; Seo, G.; Heo, S.; Park, J.; Jang, J.; Paek, S.; Garcia-Belmonte, G.; Nazeeruddin, M. K. Selective growth of layered perovskites for stable and efficient photovoltaics . Energy & ...

    2018

  52. [60]

    M.; Jeong, K.; Choi, K.; Choi, M.; Noh, J

    Jang, Y.-W.; Lee, S.; Yeom, K. M.; Jeong, K.; Choi, K.; Choi, M.; Noh, J. H. Intact 2D/3D halide junction perovskite solar cells via solid-phase in-plane growth . Nature Energy 2021, 6, 63--71

    2021

  53. [61]

    A.; Caprioglio, P.; Drigo, N.; Hofstetter, Y

    Sutanto, A. A.; Caprioglio, P.; Drigo, N.; Hofstetter, Y. J.; Garcia-Benito, I.; Queloz, V. I.; Neher, D.; Nazeeruddin, M. K.; Stolterfoht, M.; Vaynzof, Y.; Grancini, G. 2D/3D perovskite engineering eliminates interfacial recombination losses in hybrid perovskite solar cells ....

    2021

  54. [62]

    H.; Grancini, G

    Teale, S.; Degani, M.; Chen, B.; Sargent, E. H.; Grancini, G. Molecular cation and low-dimensional perovskite surface passivation in perovskite solar cells . Nature Energy 2024, 9, 779--792

    2024

  55. [63]

    P.; Pan, D.; Dang, L.; Wright, J

    Fu, Y.; Zheng, W.; Wang, X.; Hautzinger, M. P.; Pan, D.; Dang, L.; Wright, J. C.; Pan, A.; Jin, S. Multicolor Heterostructures of Two-Dimensional Layered Halide Perovskites that Show Interlayer Energy Transfer . Journal of the American Chemical Society 2018, 140, 15675--15683

    2018

  56. [64]

    Heterojunction formed via 3D-to-2D perovskite conversion for photostable wide-bandgap perovskite solar cells

    Wen, J.; Zhao, Y.; Wu, P.; Liu, Y.; Zheng, X.; Lin, R.; Wan, S.; Li, K.; Luo, H.; Tian, Y.; Li, L.; Tan, H. Heterojunction formed via 3D-to-2D perovskite conversion for photostable wide-bandgap perovskite solar cells . Nature Communications 2023, 14, 7118

    2023

  57. [65]

    Merrifield, R. E. Theory of Magnetic Field Effects on the Mutual Annihilation of Triplet Excitons . The Journal of Chemical Physics 1968, 48, 4318--4319

    1968

  58. [66]

    C.; Merrifield, R

    Johnson, R. C.; Merrifield, R. E. Effects of Magnetic Fields on the Mutual Annihilation of Triplet Excitons in Anthracene Crystals . Physical Review B 1970, 1, 896--902

    1970

  59. [67]

    Merrifield, R. E. Magnetic effects on triplet exciton interactions . Pure and Applied Chemistry 1971, 27, 481--498

    1971

  60. [68]

    Ern, V.; Merrifield, R. E. Magnetic Field Effect on Triplet Exciton Quenching in Organic Crystals . Physical Review Letters 1968, 21, 609--611

    1968

  61. [69]

    E.; Geacintov, B

    Swenburg, C. E.; Geacintov, B. E.; Birks, J. B. In Organic molecular photophysics ; Birks, J. B., Ed.; 1973; Vol. 1; pp 521--523

    1973

  62. [70]

    Triplet–charge annihilation versus triplet–triplet annihilation in organic semiconductors

    Shao, M.; Yan, L.; Li, M.; Ilia, I.; Hu, B. Triplet–charge annihilation versus triplet–triplet annihilation in organic semiconductors . J. Mater. Chem. C 2013, 1, 1330--1336

    2013

  63. [71]

    J.; Hontz, E.; Congreve, D

    Thompson, N. J.; Hontz, E.; Congreve, D. N.; Bahlke, M. E.; Reineke, S.; Van Voorhis, T.; Baldo, M. A. Nanostructured Singlet Fission Photovoltaics Subject to Triplet‐Charge Annihilation . Advanced Materials 2014, 26, 1366--1371

    2014

  64. [72]

    Interfacial electronic structures revealed at the rubrene/CH _3 NH _3 PbI _3 interface

    Ji, G.; Zheng, G.; Zhao, B.; Song, F.; Zhang, X.; Shen, K.; Yang, Y.; Xiong, Y.; Gao, X.; Cao, L.; Qi, D.-c. Interfacial electronic structures revealed at the rubrene/CH _3 NH _3 PbI _3 interface . Physical Chemistry Chemical Physics 2017, 19, 6546--6553

    2017

  65. [73]

    P.; Bailey, C

    Sloane, N. P.; Bailey, C. G.; Cole, J. H.; Schmidt, T. W.; McCamey, D. R.; Klymenko, M. V. Electronic Structure at the Perovskite/Rubrene Interface: The Effect of Surface Termination . The Journal of Physical Chemistry C 2025, 129, 889--898

    2025

  66. [74]

    Tang, J.; Lin, Y.; Yan, H.; Lin, J.; Rao, H.; Pan, Z.; Zhong, X. 20.1 \

  67. [75]

    G.; Gillan, L

    Bailey, C. G.; Gillan, L. V.; Lee, M.; Sloane, N.; Liu, X.; Hao, X.; Soufiani, A. M.; McCamey, D. R. Influence of Organic Spacer Cation on Dark Excitons in 2D Perovskites . Advanced Functional Materials 2024, 34, 2308095

    2024

  68. [76]

    G.; Mena, A.; Leung, T

    Bailey, C. G.; Mena, A.; Leung, T. L.; Sloane, N. P.; Liao, C.; McKenzie, D. R.; McCamey, D. R.; Ho-Baillie, A. Revealing localised dark-exciton populations in 2D perovskites via magneto-optical microscopy . 2025,

    2025

  69. [77]

    Y.; Khoury, T.; Clady, R

    Cheng, Y. Y.; Khoury, T.; Clady, R. G.; Tayebjee, M. J.; Ekins-Daukes, N. J.; Crossley, M. J.; Schmidt, T. W. On the efficiency limit of triplet–triplet annihilation for photochemical upconversion . Physical Chemistry Chemical Physics 2009, 12, 66--71

    2009

  70. [78]

    S.; Castellano, F

    Haefele, A.; Blumhoff, J.; Khnayzer, R. S.; Castellano, F. N. Getting to the (Square) root of the problem: How to make noncoherent pumped upconversion linear . Journal of Physical Chemistry Letters 2012, 3, 299--303

    2012

  71. [79]

    W.; Zhang, W.; Burlakov, V

    deQuilettes, D. W.; Zhang, W.; Burlakov, V. M.; Graham, D. J.; Leijtens, T.; Osherov, A.; Bulovi \' c , V.; Snaith, H. J.; Ginger, D. S.; Stranks, S. D. Photo-induced halide redistribution in organic–inorganic perovskite films . Nature Communications 2016, 7, 11683

    2016

  72. [80]

    Mechanisms and Suppression of Photoinduced Degradation in Perovskite Solar Cells

    Wei, J.; Wang, Q.; Huo, J.; Gao, F.; Gan, Z.; Zhao, Q.; Li, H. Mechanisms and Suppression of Photoinduced Degradation in Perovskite Solar Cells . Advanced Energy Materials 2021, 11, 2002326

    2021

  73. [81]

    Grancini, G.; Rold \' a n-Carmona, C.; Zimmermann, I.; Mosconi, E.; Lee, X.; Martineau, D.; Narbey, S.; Oswald, F.; De Angelis, F.; Graetzel, M.; Nazeeruddin, M. K. One-Year stable perovskite solar cells by 2D/3D interface engineering . Nature Communications 2017, 8, 1--8

    2017

  74. [82]

    Advancing 2D Perovskites for Efficient and Stable Solar Cells: Challenges and Opportunities

    Zhao, X.; Liu, T.; Loo, Y. Advancing 2D Perovskites for Efficient and Stable Solar Cells: Challenges and Opportunities . Advanced Materials 2022, 34, 2105849

    2022

  75. [83]

    Vertically Oriented 2D Layered Perovskite Solar Cells with Enhanced Efficiency and Good Stability

    Zhang, X.; Wu, G.; Yang, S.; Fu, W.; Zhang, Z.; Chen, C.; Liu, W.; Yan, J.; Yang, W.; Chen, H. Vertically Oriented 2D Layered Perovskite Solar Cells with Enhanced Efficiency and Good Stability . Small 2017, 13, 1700611

    2017

  76. [84]

    o hler, Anna and B \

    Chen, A. Z.; Shiu, M.; Ma, J. H.; Alpert, M. R.; Zhang, D.; Foley, B. J.; Smilgies, D.-M.; Lee, S.-H.; Choi, J. J. Origin of vertical orientation in two-dimensional metal halide perovskites and its effect on photovoltaic performance . Nature Communications 2018, 9, 1336 mcitet...

    2018 arXiv

  77. [85]

    write newline

    " write newline "" before.all 'output.state := FUNCTION n.dashify 't := "" t empty not t #1 #1 substring "-" = t #1 #2 substring "--" = not "--" * t #2 global.max substring 't := t #1 #1 substring "-" = "-" * t #2 global.max substring 't := while if t #1 #1 substring * t #2 gl...

Pith tools

Reviewed August 15, 2026 · model on record in the stance chip above.