Enhanced photoresponse through van der Waals heterostructure integration: p-GaSe and n-MoSe2 on h-BN substrate

Abstract

Attention towards heterostructures developed using 2D materials has surged due to their versatile capabilities in electronic devices. In our study, we introduce and investigate a van der Waals heterostructure comprising p-type gallium selenide (p-GaSe) and n-type molybdenum diselenide (n-MoSe₂), featuring pure ohmic interactions and high gate-modulated improvement. We obtained a significant rectification ratio of 6.3 × 10⁵, which is attributed to an uncontaminated interface of p-GaSe and n-MoSe₂, associated with reduced Schottky barriers. The optoelectronic characteristics were evaluated when exposed to an incident light of wavelength (λ) of 532 nm and various power intensities ranging from 20 to 100 nW. Our findings demonstrated a notable photoresponsivity of 2.4 × 10³ A W⁻¹ through external quantum efficiency (EQE) of 5.59 × 10⁵%. The device exhibited a rapid rise of 2.2 μs and a decay time of 4.8 μs. Moreover, the p-GaSe/n-MoSe₂ heterostructure exhibited exceptional performance as a binary CMOS rectifier and inverter. These tools, constructed on transition metal dichalcogenide (TMD) heterostructures, hold promise for enhancing energy harvesting capabilities and multifunctional logic switches.