Highly Weak-light Sensitive and Dual-band Switchable Photodetector Based on CuI/Si Unilateral Heterojunction  

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

作　　者：YANG Jialin WANG Liangjun RUAN Siyuan JIANG Xiulin YANG Chang 杨佳霖;王亮君;阮丝园;蒋秀林;杨长(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;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)

机构地区：[1]Key Laboratory of Polar Materials and Devices(MOE),Shanghai Center of Brain-inspired Intelligent Materials and Devices,Department of Electronics,East China Normal University,Shanghai 200241,China [2]Institute of Intelligent Flexible Mechatronics,Jiangsu University,Zhenjiang 212013,China [3]Cell R&D Center,JA Solar Holdings Co.,Ltd,Yangzhou 225000,China

出　　处：《无机材料学报》2024年第9期1063-1069,共7页Journal of Inorganic Materials

基　　金：National Natural Science Foundation of China(62074056);Fundamental Research Funds for the Central Universities。

摘　　要：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 7.6×10^(4),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 10^(13)-1014 Jones can be achieved with a power density as low as 0.5μW/cm^(2),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.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7.6×10^(4)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0.5μW/cm^(2)时,其具有高达10^(13)~10^(14)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。

关 键 词：er iodide HETEROJUNCTION PHOTODETECTOR 

分 类 号：TQ174[化学工程—陶瓷工业]