多孔n-GaN/p-Zn_(x)Cu_(1-x)S异质结的制备及紫外探测性能研究  

Preparation and Ultraviolet Detection Performance Study of Porous n-GaN/p-Zn_(x)Cu_(1-x)S Heterojunctions

作　　者：杜志伟 贾伟[1,2] 贾凯达 任恒磊 李天保 董海亮[1] 贾志刚[1] 许并社 DU Zhiwei;JIA Wei;JIA Kaida;REN Henglei;LI Tianbao;DONG Hailiang;JIA Zhigang;XU Bingshe(Key Laboratory of Interface Science and Engineering in Advanced Materials Ministry of Education,Taiyuan University of Technology,Taiyuan 030024,China;Shanxi-Zheda Institute of Advanced Materials and Chemical Engineering,Taiyuan 030024,China;Institute of Atomic and Molecular Science,Shaanxi University of Science and Technology,Xi’an 710021,China)

机构地区：[1]太原理工大学新材料界面科学与工程教育部重点实验室,太原030024 [2]山西浙大新材料与化工研究院,太原030024 [3]陕西科技大学材料原子·分子科学研究所,西安710021

出　　处：《人工晶体学报》2024年第8期1326-1336,共11页Journal of Synthetic Crystals

基　　金：山西浙大新材料与化工研究院(2021SX-AT002);山西省重点研发计划项目(202302150101012);山西省自然科学基金(201901D111109);山西省重点研发项目(201903D111009)。

摘　　要：本文首先采用紫外光辅助电化学刻蚀(UV-EC)方法制备出了孔隙密度为1.51×10^(10)cm^(-2)、平均孔径为38 nm的多孔n-GaN薄膜;随后在其上通过水浴法沉积了一系列Zn_(x)Cu_(1-x)S复合薄膜,x为0.0、0.2、0.4、0.6、0.8、1.0,形成的多孔n-GaN/p-Zn_(x)Cu_(1-x)S异质结带隙在2.34~3.51 eV调控;最后基于这些异质结构建出p-n结型紫外探测器。I-V曲线结果表明这些探测器均具有良好的整流特性,特别是n-GaN/p-Zn_(0.4)Cu_(0.6)S探测器性能最优。在暗态下,I_(+3 V)/I_(-3 V)约为1.78×10^(5);在偏压为-3 V、光功率密度为432μW/cm^(2)(365 nm)的条件下,光暗电流比超过10^(3),上升/下降时间为0.09/39.8 ms,响应度(R)为0.352 A/W,外量子效率(EQE)为119.6%,探测率(D^(*))为3.21×10^(12)Jones。I-t曲线结果表明,多孔n-GaN/p-Zn_(x)Cu_(1-x)S异质结紫外探测器在连续开-关光循环过程中拥有稳定的光电流响应。该研究为制备异质结紫外探测器提供了一定的理论指导和实验数据。In this paper,porous n-GaN thin films with a pore density of 1.51×10^(10) cm^(-2) and an average pore size of 38 nm were initially prepared by UV-assisted electrochemical etching(UV-EC).Subsequently,a series of Zn_(x)Cu_(1-x)S composite films,with x values of 0.0,0.2,0.4,0.6,0.8 and 1.0,were deposited on the porous n-GaN films by water bath method.The bandgaps of the porous n-GaN/Zn_(x)Cu_(1-x)S heterojunctions varied in the range from 2.34 eV to 3.51 eV.Hall test results demonstrate that when x values is less than 1,the Zn_(x)Cu_(1-x)S composite films exhibit p-type semiconductor properties.Furthermore,increasing the proportion of CuS leads to an improvement in the conductivity of the composite films.Additionally,XPS results confirm that both Cu and Zn possess a +2 valence within the composite films.When Zn_(x)Cu_(1-x)S forms a heterojunction with porous n-GaN,the energy band structures of both materials interact to create a built-in electric field.This field facilitates the efficient separation of photogenerated electron-hole pairs.Finally,p-n heterojunctions UV detectors were constructed based on these heterostructures.The I-V curve results indicate that these detectors exhibit good rectification characteristics.Notably,the n-GaN/p-Zn_(0.4)Cu_(0.6)S detector demonstrates optimal performance.In the dark state,I_(+3 V)/I_(-3 V) is approximately 1.78×10^(5).Under a bias voltage of-3 V and an optical power density of 432 μW/cm^(2)(ultraviolet light at 365 nm),this detector's photo-to-dark current ratio exceeds 10~3,the rise/fall time is 0.09/39.8 ms,responsivity(R) reaches 0.352 A/W,the external quantum efficiency(EQE) stands at 119.6%,and detectivity(D^(*)) is 3.21×10^(12) Jones.The I-t curve results indicate that the porous n-GaN/p-Zn_(x)Cu_(1-x)S heterojunctions UV detector possesses reproducible performance during the consecutive on-off optical cycling process with reproducible photocurrent response.This study offers valuable theoretical insights and a comprehensive understanding of the physical properties

关 键 词：p-Zn_(x)Cu_(1-x)S 多孔n-GaN 异质结 紫外探测器 光暗电流比 响应度 

分 类 号：O475[理学—半导体物理] TB383.2[理学—物理] TN23[一般工业技术—材料科学与工程]