高载流子迁移率胶体量子点红外探测器  

Infrared Detectors of High Carrier Mobility Colloidal Quantum Dots

作　　者：薛晓梦 马海菲 郝群[1,2] 唐鑫 陈梦璐 Xue Xiaomeng;Ma Haifei;Hao Qun;Tang Xin;Chen Menglu(School of Optics and Photonics,Beijing Institute of Technology,Beijing 100081,China;Yangtze Delta Region Academy of Beijing Institute of Technology,Jiaxing 314019,Zhejiang,China)

机构地区：[1]北京理工大学光电学院,北京100081 [2]北京理工大学长三角研究院,浙江嘉兴314019

出　　处：《光学学报》2023年第22期49-56,共8页Acta Optica Sinica

基　　金：国家自然科学基金(U22A2081,62105022);中国科学技术协会青年托举工程(YESS20210142);北京市科技新星计划(Z211100002121069)。

摘　　要：采用混相配体交换的方法成功实现了载流子迁移率近2个量级的提升,达到1 cm^(2)/(V·s),同时还可以灵活调控N型、本征型和P型等掺杂类型。在此基础上,使用本征型碲化汞胶体量子点薄膜制备短波及中波红外光伏型探测器。截止波长为1.9μm的短波红外探测器在300 K下的响应率为0.9 A/W,比探测率为4×10^(11)Jones;截止波长为4.2μm的中波红外探测器在110 K下的响应率为1.1 A/W,比探测率为1.2×10^(11)Jones。在没有施加偏置电压的情况下,300 K下的短波红外光电探测器的外量子效率可以达到61%,110 K下的中波红外光电探测器的外量子效率可以达到30%。Objective Short-wave infrared(SWIR)and mid-wave infrared(MWIR)bands catch much attention because of matching the atmosphere window.In this spectral range,solution-based zinc-blend HgTe colloidal quantum dots(CQDs)become a potential alternative to traditional epitaxial materials for photodetection.However,the performance of CQD photodetectors should be improved,and controlling the transport properties like doping and mobility would be the key to high-performance photodetectors.We employ the mixed phase ligand exchange method to achieve high carrier mobility in HgTe CQDs films,which is more than 1 cm^(2)/(V·s).Meanwhile,different doping types in HgTe CQD solid are realized,such as N,intrinsic,and P types.We also demonstrate that the high carrier mobility improves CQD photovoltaic performance.For example,SWIR and MWIR photovoltaic photodetectors are achieved with intrinsic high mobility HgTe CQDs solid,where the external quantum efficiency(EQE)is 61%for SWIR photovoltaic photodetectors and 30%for MWIR photovoltaic photodetectors.Additionally,the detectivity(D*)is 4×10^(11)Jones at 300 K for SWIR photovoltaic photodetectors and 1.2×10^(11)Jones at 110 K for MWIR photovoltaic photodetectors.Methods The mixed-phase ligand exchange process involves liquid-phase ligand exchange and solid-phase ligand exchange.In the liquid phase ligand exchange,4 mL HgTe CQDs in n-hexane would mix with 160μLβ-ME and 8 mg DDAB in DMF,which is stewed for 10 s to accelerate separation.Then the solution is centrifuged,and after decanting the supernatant,60μL DMF is adopted to dissolve the CQD solids in centrifuge tubes to obtain stable CQD ink.In this method,β-ME replaces the long-chain ligand on the CQD surface in the liquid phase,and DDAB is a catalyst to assist CQDs transfer from n-hexane to the polar solvent DMF.The CQD films are prepared by spin or drop coating,and then solid-state ligand exchange with EDT/HCl/IPA(1∶1∶50 by volume)solution is performed for 10 s,rinsed with IPA,and dried with N2.Solid-phase ligand exchange can

关 键 词：探测器 量子点 高迁移率 光伏型红外光电探测器 配体交换 

分 类 号：TH745[机械工程—光学工程]