Gate-controlled rectification and broadband photodetection in a P–N diode based on TMDC heterostructures

Abstract

van der Waals (vdW) heterostructures in two dimensions have electrical and optoelectronic characteristics that make them a suitable platform for the creation of sophisticated nanoscale electronic devices. Outstanding p–n heterojunctions made of two-dimensional atomic layers are essential for the realization of superior integrated optoelectronics. This article shows how WSe₂ and SnS₂ layers are stacked by vdW heterostructures to build a p–n junction diode over Si/SiO₂ substrates; Raman mapping confirms the heterostructure even further. The WSe₂/SnS₂ vdW heterostructure's electrical attributes show ultra-low dark currents because of the junction's depletion area and robust direct current passage when lit. An energy band diagram is also used to study and describe the charge transport process. When the back-gate voltage is swept effectively, 2.9 × 10⁴ is the rectification ratio (RR). The photovoltaic characteristics of the WSe₂/SnS₂ heterostructure have been studied under irradiation of light with different wavelengths (λ). When 220 nm light is applied to the WSe₂/SnS₂ vdW heterostructure, a change in the photocurrent of 65 nA is observed. Under light irradiation of deep ultraviolet (DUV) light at λ = 220 nm and V_ds = 0.5 V, the device revealed a responsivity (R) of 1.31 × 10⁵ m AW⁻¹, with a substantial EQE of 7.3 × 10⁴ (%) and a detectivity (D*) of around 3.13 × 10¹⁰ Jones. The creation of these superior p–n junctions opens the door for the production of logical and effective optoelectronic devices.