p-WSe2 Nanosheets/ n-WS2 Quantum Dots/p-Si (2D-0D-3D) Mixed-Dimensional Multilayer Heterostructures Based High-Performance Broadband Photodetector

Abstract

In this work, we have investigated the performance of a p-WSe ₂ Nanosheets (NSs)/n-WS ₂ Quantum dots (QDs)/p-Si (2D-0D-3D) based mixed-dimensional (MD) multilayer heterostructure photodetector with Ag as top contact electrode. The WSe ₂ NSs and WS ₂ QDs are synthesized by solvothermal and hydrothermal synthesis methods, respectively. The proposed photodetector exhibits a broad photo response over 300 nm (ultraviolet) to 1100 nm (infrared) with the maximum responsivity (R) of 2.14×10 ² A/W, detectivity (D ^* ) of 2.35×10 ¹³ Jones, and external quantum efficiency (EQE) of 82710% at 322 nm and -3 V reverse bias voltage. The measured rise time and fall time of the device are 24 ms and 21 ms, respectively. Our proposed p-WSe ₂ NS/n-WS ₂ QDs/p-Si (2D-0D-3D) photodetector is shown to have nearly ∼ 8 times higher values of R and EQE, 17 times higher value of D ^* , 34 times lower value of the rise time and 38 times lower value of the fall time as compared to the respective performance parameters of the n-WS ₂ QDs/p-Si (0D-3D) MD heterojunction photodetector.