基于CuI/Si单边异质结的微光高灵敏双波段可切换光电探测器
Highly Weak-light Sensitive and Dual-band Switchable Photodetector Based on CuI/Si Unilateral Heterojunction
杨佳霖 1王亮君 1阮丝园 1蒋秀林 2杨长1
作者信息
- 1. 华东师范大学 电子系,极化材料与器件教育部重点实验室,上海类脑智能材料与器件研究中心,上海 200241
- 2. 江苏大学智能柔性机械电子研究院,镇江 212013;晶澳太阳能有限公司 电池研发中心,扬州 225000
- 折叠
摘要
近年来,碘化铜(CuI)因其较高的本征霍尔迁移率、高光吸收和较大的激子结合能而成为一种新兴的p型宽带隙半导体.然而,在传统半导体材料表面制备高质量CuI薄膜非常困难,已有Cui基异质结器件的光谱响应和光电转换效率较低.本研究采用一种简易的金属碘化法制备了一种p-CuI/n-Si结构的光电二极管.虽然获得的CuI是带有明显结构缺陷的多晶薄膜,但CuI/Si二极管具有很高的弱光灵敏度.其高达7.6×104的整流比表明该光电二极管具有良好的缺陷容忍度,这与p+n型二极管的单边异质结这一特殊结构有关.本研究对该p+n型二极管的光电响应进行了较为系统的研究,选择波长分别为400、505、635和780 nm的不同单色激光器进行光响应测试.在零偏置电压条件下,该器件为单边异质结,耗尽层仅在硅一侧,因此只有可见光被吸收.当施加-3 V的偏置电压时,光电二极管被切换到"紫外-可见"双波段响应的工作模式.因此,通过调整偏置电压可以使检测波长在"可见"波段和"紫外-可见"波段之间切换.此外,本研究所得到的CuI/Si二极管对弱光照非常敏感.在入射光功率密度低至0.5 μW/cm2时,其具有高达1013～1014 Jones的探测率,明显优于其他铜基光电二极管.相关研究结果证实了 Cui在与传统硅工业集成时的高应用潜力.
Abstract
In recent years,copper iodide(Cui)is an emerging p-type wide bandgap semiconductor with high intrinsic Hall mobility,high optical absorption and large exciton binding energy.However,the spectral response and the photoelectric conversion efficiency are limited for Cui-based heterostructure devices,which is related to the difficulty in fabrication of high-quality Cui thin films on other semiconductors.In this study,a p-CuI/n-Si photodiode has been fabricated through a facile solid-phase iodination method.Although the CuI thin film is polycrystalline with obvious structural defects,the CuI/Si diode shows a high weak-light sensitivity and a high rectification ratio of 7.6× 104,indicating a good defect tolerance.This is because of the unilateral heterojunction behavior of the formation of the p n diode.In this work,the mechanism of photocurrent of the p+n diode has been studied comprehensively.Different monochromatic lasers with wavelengths of 400,505,635 and 780 nm have been selected for testing the photoresponse.Under zero-bias voltage,the device is a unilateral heterojunction,and only visible light can be absorbed at the Si side.On the other hand,when a bias voltage of-3 V is applied,the photodiode is switched to a broader"UV-visible"band response mode.Therefore,the detection wavelength range can be switched between the"Visible"and"UV-visible"bands by adjusting the bias voltage.Moreover,the obtained CuI/Si diode was very sensitive to weak light illumination.A very high detectivity of 1013-1014 Jones can be achieved with a power density as low as 0.5 μW/cm2,which is significantly higher than that of other Cu-based diodes.These findings underscore the high application potential of CuI when integrated with the traditional Si industry.
关键词
碘化铜/异质结/光电探测器Key words
copper iodide/heterojunction/photodetector引用本文复制引用
基金项目
National Natural Science Foundation of China(62074056)
Fundamental Research Funds for the Central Universities()
出版年
2024
国家科技期刊平台
NSTL
万方数据