文献类型：期刊文献

中文题名：新型NiO-Bi_(2)Te_(3)异质结光电探测器的制备与光响应性能研究

英文题名：Fabrication and Photoresponse Study of the Photodetector Based on Novel NiO-Bi_(2)Te_(3) Heterostructure

作者：施名刚[1];牟海川[1];钱敏[1]

机构：[1]华东理工大学物理学院,上海200237

年份：2022

卷号：51

期号：2

起止页码：137

中文期刊名：光子学报

外文期刊名：Acta Photonica Sinica

收录：CSTPCD;;EI(收录号：20221311863325);Scopus;WOS:【ESCI(收录号:WOS:000808045500032)】；北大核心:【北大核心2020】；CSCD:【CSCD2021_2022】；

基金：National Natural Science Foundation of China (No. 61804054), Natural Science Foundation of Shanghai (No. 18ZR1410400)

语种：中文

中文关键词：氧化镍;碲化铋;纳米金;异质结;光电探测器

外文关键词：Nickel Oxide;Bismuth Telluride;Au nanoparticles;Heterojunction;Photodetector

摘要：采用旋涂法制备氧化镍(NiO)薄膜,用化学气相沉积法在其表面生长碲化铋(Bi_(2)Te_(3)),形成NiO/Bi_(2)Te_(3)异质结,采用X射线衍射、拉曼光谱、扫描电镜、能量色散光谱以及光致发光光谱来表征异质结材料。研究了Ni^(2+)浓度对光电探测器的光谱响应和光功率响应的影响。结果表明Ni^(2+)浓度为0.5 mol/L时器件表现出最佳的光响应性能。研究还发现NiO中掺入纳米金颗粒(AuNPs)可以显著提升器件的光响应性能。本文研究验证了在FTO/NiO+AuNPs/Bi_(2)Te_(3)/Ag结构中,两个内建电场和AuNPs对光响应性能提升的叠加效应,为NiO在光电探测领域的应用提供了借鉴。
As a significant p-type semiconductor,NiO is widely studied for its gas sensing and electrochromism characteristics,whereas researches concerning its photodetection properties are rarely reported.Herein,we fabricated a photodetector based on NiO/Bi_(2)Te_(3) heterostructure and studied the influence of NiO’s concentrations as well as the Localized Surface Plasmon Resonance(LSPR)effect of the Au NPs on the device’s photoresponse.For the device fabrication,NiO film was spin-coated on the FTO glass,followed by baking and annealing to form high quality crystal film.Then,Chemical Vapor Deposition(CVD)method was adopted to lay Bi_(2)Te_(3) nanoplates on the NiO film,forming the NiO-Bi_(2)Te_(3) heterostructure.Finally,the device was achieved via photolithographic process and Ag electrodes deposition,featuring a vertical structure with FTO working as the anode and Ag serving as the cathode.X-Ray Diffraction(XRD)and Scanning Electron Microscope(SEM)results demonstrate the favorable crystal quality of NiO film and Bi_(2)Te_(3) nanoplates.Energy Dispersive Spectrometer(EDS)image manifests the uniform distribution of different elements and Photoluminescence(PL)spectra were applied to study the mechanism of electron-hole separation.All these results could be condensed to the point that the NiO film with the concentration of 0.5 mol/L shows the optimal crystal quality and the doping of Au NPs aids the separation of electron-hole pairs.Furthermore,we also performed photo-electric tests to evaluate the influence of the NiO concentration and the results show that the device achieves optimal response with the concentration of NiO fixed at 0.5 mol/L,which meshes well with the characterizing results.In addition,tests regarding photoresponse to wavelength,power density and on/off switching were conducted in ambient environment.With the presence of Au NPs,the maximum responsivity(R)of the device reaches 1236 mA/W,about 21%higher compared to that of the pristine NiO,owing to the boosted light absorption caused by the LSPR effect of Au NPs.To elucidate the weak signal detecting ability,the specific detectivity(D*)of the device is calculated and it attains the value of 5.97×10^(10) Jones.Besides,the photo gain exceeds 400%,indicating that there are more than 4 photoexcited carriers generated by per absorbed photon.Beyond that,the formation of Schottky contact between NiO and Au NPs will facilitate the separation of electron-hole pairs,thus accelerating the response process and shrinking the rise time(Tr)and decay time(Td)to 92 ms and 62 ms,respectively.The study corroborates the enhancement of photoresponse resulted from the two internal electrical field due to the introduction of NiO/Bi_(2)Te_(3) junction and Au/NiO Schottky junction as well as the LSPR effect from Au NPs.This research offers a feasible approach for the realization of NiO-based photodetector and sheds light on the enormous potential of the NiO’s application in photodetection.