Pyroelectric doping reversal of MoS2 p-n junctions on ferroelectric domain walls probed by photoluminescence

Tailoring the optical properties and electronic doping in transition metal dichalcogenides (TMDs) is a central strategy for developing innovative systems with tunable characteristics. In this context, pyroelectric materials, which hold the capacity for charge generation when subjected to temperature changes, offer a promising route for this modulation. This work employs spatially resolved photoluminescence (PL) to explore the impact of pyroelectricity on the electronic doping of monolayer MoS2 deposited on periodically poled LiNbO3 (LN) substrates. The results demonstrate that pyroelectricity in LN modulates the charge carrier density in MoS2 on ferroelectric surfaces acting as doping mechanism without the need for gating electrodes. Furthermore, upon cooling, pyroelectric charges effectively reverse the doping of p-n junctions on DWs, converting them into n-p junctions. These findings highlight the potential of pyroelectric substrates for tunable and configurable charge engineering in transition metal dichalcogenides and suggest their applicability to other combinations of 2D materials and ferroelectric substrates. They also open avenues for alternative device architectures in nanoelectronic or nanophotonic devices including switches, memories or sensors.