ZnO/Spiro-MeOTAD异质结自驱动光电探测器的制备及性能(特邀)  

Preparation and Properties of ZnO/Spiro-MeOTAD Heterojunction Self-powered Photodetector(Invited)

作　　者：李朋凡 黄雨欣 俞学伟 冯仕亮 姜岩峰 闫大为 于平平 LI Pengfan;HUANG Yuxin;YU Xuewei;FENG Shiliang;JIANG Yanfeng;YAN Dawei;YU Pingping(Department of Electronic Engineering,Institute of Advanced Technology,Jiangnan University,Wuxi 214122,China)

机构地区：[1]江南大学先进技术研究院,电子工程系,无锡214122

出　　处：《光子学报》2024年第7期58-67,共10页Acta Photonica Sinica

基　　金：国家自然科学基金(No.51802124);江苏省自然科学基金(No.BK20180626)。

摘　　要：ZnO具有高稳定性、低成本、宽带隙等优点,被广泛用于光电探测器但响应速度较慢,采用Zn(TFSI)2和CNT∶TiO_(2)作为混合掺杂剂来代替Li-TFSI,以提高Spiro-MeOTAD的稳定性及光电性能,采用旋涂法制备了ZnO/Spiro-MeOTAD异质结构筑光电探测器。ZnO/Spiro-MeOTAD光电探测器在250~600 nm波长范围内,具有良好的自驱动特性。在0 V条件下,ZnO/Spiro-MeOTAD器件在368 nm的入射光照射下具有最高的光电性能,响应度为27.34 mA W^(-1),比探测率为3.62×10^(11)Jones,开关比为2029,上升/下降时间分别为0.71 s/0.55 s,相较于ZnO的光电性能(响应度为17.74 mA·W^(-1),比探测率为5.11×10^(10)Jones,开关比为63.6,上升/下降时间为11.76 s/1.49 s)分别提升提高了1.5倍、7倍、32倍。ZnO/Spiro-MeOTAD器件在550 nm处仍具有明显响应,响应度和比探测率分别为2.48 mA·W^(-1)和3.32×10^(10)Jones,对比ZnO器件提高了248倍和940倍。不同放置时间(1个月)和预处理温度(0~140℃)下光电流的变化,验证了Spiro-MeOTAD加入构筑p-n异质结,不仅可以显著提升ZnO基光电探测器的响应度、开关比和响应速度,同时使得探测器具有良好的稳定性,可以应用于较高温度工作环境。A photodetector is a sensing element capable of converting an optical signal into an electrical signal.ZnO is widely used in photodetectors due to high stability,low cost and wide band gap,however the long response speed limits their development.The photoelectric performances of ZnO can be effectively improved by fabricating the inorganic-organic heterostructure.The Li-TFSI doped Spiro-MeOTAD as one of organic semiconductor exhibits high hole regeneration ability,high conductivity and the hole mobility,but the stability is low.In this paper,Zn(TFSI)_(2) and CNT∶TiO_(2)are used as mixed dopants to replace Li-TFSI to improve the conductivity and stability of Spiro-MeOTAD and achieve higher photoelectric performances.The doped Spiro-MeOTAD is closely combined with ZnO thin films by spinning coating method.ZnO/Spiro-MeOTAD photodetectors were prepared by Ag paste as electrodes covered on the ZnO thin films and ZnO/Spiro-MeOTAD heterojunction,respectively.The morphologies and structure of ZnO,Spiro-MeOTAD and ZnO/Spiro-MeOTAD devices were characterized by scanning electron microscope,X-ray diffractometer,Raman spectrum,UV-Vis absorption spectrum,suggesting the successful preparation of ZnO/Spiro-MeOTAD heterojunction.The thickness of the ZnO film is about 9μm,while the thickness of Spiro-MeOTAD is about 400 nm,suggesting the thin Spiro-MeOTAD is benefit to the light absoption and photodetection performances.The optical absorption coefficient of ZnO/Spiro-MeOTAD is higher than that of ZnO in the whole wavelength range,and is significantly improved in the wavelength range of 350~450 nm.The addition of Spiro-MeOTAD extends the absorption cutoff edge of ZnO and expands the response wavelength range.Under dark conditions,the forward bias voltage and the reverse bias voltage of ZnO/Spiro-MeOTAD devices have different current change rates,showing a rectification effect with the rectification ratio of 28±2.The open circuit voltage and short circuit current of the device under 368 nm illumination are 0.4 V and 14 nA respec

关 键 词：光电探测器 异质结 旋涂法 ZNO Spiro-MeOTAD 自驱动 

分 类 号：O472.8[理学—半导体物理] TN15[理学—物理]