Voltage-regulated photoluminescence modulation in a 0D-2D mixed dimensional heterostructure

Abstract

Bias-dependent oscillations in excitonic photoluminescence are observed in a mixed-dimensional 0D–2D heterostructure. These oscillations arise from modulation by oscillatory DC photocurrent, which exhibits periodic negative differential resistance, indicating recurring charge accumulation within the heterostructure. The persistence of these oscillations across a macroscopic area of diameter ~200 μm suggests the presence of periodically correlated quantum phenomena over large length scales. Furthermore, bias-dependent oscillations in the photo-capacitance are observed, reflecting a periodic ordering and disordering of excitonic populations. Together, these observations point to a direct competition between coherent and incoherent electron tunnelling processes. The coupled oscillatory behaviour of photoluminescence, photocurrent, and photo-capacitance highlights new opportunities for exciton-based quantum optoelectronic devices.