Integration of photovoltaic and photogating effects in a WSe₂/WS₂/p-Si dual junction photodetector featuring high-sensitivity and fast-response

Abstract

Two-dimensional (2D) materials-based van der Waals (vdW) heterostructures with exotic semiconducting properties have shown tremendous potential in next-generation photovoltaic photodetectors. Nevertheless, these vdW heterostructure devices inevitably suffer a compromise between...

ReS2 Nanosheet/WS2 Nanosheet/p-GaN Substrate Dual Junction Photodetectors

“…Additionally, Figure c displays the Raman spectra of the dual junction device at four different positions. The red and yellow curves represent the Raman spectra of the WS 2 and WS 2 /GaN regions, respectively, where two prominent peaks of E 2g and A 1g consistently appear, aligning with the typical Raman modes of WS 2 . − The green curve illustrates the Raman spectrum of the ReS 2 region, exhibiting a strong A g characteristic peak at 158.04 cm –1 along with other weaker Raman peaks. , The purple curve corresponds to the Raman spectrum of the ReS 2 /WS 2 /GaN region, demonstrating a combined peak of WS 2 and ReS 2 , indicating the successful production of high-quality vdWs heterostructures through the transfer process. High-resolution transmission electron microscopy (HRTEM) images in Figure S2 confirm the highly crystalline nature of the WS 2 and ReS 2 nanosheets.…”

“…Furthermore, the relationship between I ph and P follows a power-law function (I ph ∝ P α ), where a high α (0.88) signifies minimal loss of photoexcited carriers and an effective reduction in the compounding rate of photoexcited carriers due to the dual vdWs heterojunction structure. 47,48 Then, photodetection metrics such as responsivity (R), detection (D*), external quantum efficiency (EQE), and light on/off ratio (I on /I off ) were evaluated based on the 31 ITO/GaN, 52 MoS 2 /AlN, 53 W/GaN, 54 GaN/β-Ga 2 O 3 , 55 WSe 2 /WS 2 /p-Si, 41 Ni/GaN, 56 WS 2 /Si, 30 graphene/Si, 57 MoS 2 /p-GaN, 58 WS 2 /GaN, 35 PtSe 2 /GaN, 36 and MoS 2 /WS 2 . 59 extracted I ph in Figure 3c.…”

“…Comparison of optoelectronic performance metrics and the working mechanism of the HGW device. (a–c) Comparison of on/off ratio, responsivity, and detectivity of the constructed G , GW, HWR, HGWR, and HGW devices at V ds = 1 V. (d) Comparison of R and D * of the HGW device against those of other reported devices, including WS 2 /p-Si, ITO/GaN, MoS 2 /AlN, W/GaN, GaN/β-Ga 2 O 3 , WSe 2 /WS 2 /p-Si, Ni/GaN, WS 2 /Si, graphene/Si, MoS 2 /p-GaN, WS 2 /GaN, PtSe 2 /GaN, and MoS 2 /WS 2 . (e) Schematic diagram of the energy band structures of ReS 2 /WS 2 /p-GaN before contact.…”

Vertical 1T’‐WTe2/WS2 Schottky‐Barrier Phototransistor with Polarity‐Switching Behavior

“…As a result, Figure 1c displays the SPD image and the extracted potential profile. The averaged SPD of WTe 2 and WS 2 can be measured and calculated using the following equations: [36] eSPD WTe 2 = W tip − W WTe 2…”

“…As a result, Figure 1c displays the SPD image and the extracted potential profile. The averaged SPD of WTe 2 and WS 2 can be measured and calculated using the following equations: [ 36 ] $$$$\begin{equation}eSP{D}_{WT{e}_2} = {W}_{tip}\ - {W}_{WT{e}_2}\end{equation}$$$$ $$$$\begin{equation}eSP{D}_{W{S}_2} = {W}_{tip}\ - {W}_{W{S}_2}\end{equation}$$$$Where e is the electron charge, W tip , $${W}_{WT{e}_2}$$ and $${W}_{W{S}_2}$$ represent the work functions of KPFM tip, WTe 2 and WS 2, respectively. Therefore, after contact, the built‐in electric field points from WS 2 to the WTe 2 side.…”