摘要
近红外有机光电探测器具有低成本、可溶液旋涂、生物兼容性好和柔性可穿戴等优势,在生物传感、医学成像、柔性可穿戴电子器件等领域有广泛的应用前景。倍增型有机光电探测器相比于二极管型有机光电探测器,因其具有更高的外量子效率(EQE>100%)和灵敏度而备受关注。该类器件利用电极附近被载流子陷阱捕获的一种载流子能辅助另一种极性相反的载流子从外电路隧穿注入到活性层中,实现光电倍增,但陷阱的数量在一定程度上会影响器件性能的进一步提升。本文通过在活性层中掺入无机ZnO纳米颗粒来增加电子陷阱数量,使得器件在反向偏压保持暗电流密度的前提下,亮电流密度得到提高。通过优化,发现当ZnO纳米颗粒掺杂比例为5%时性能最优,在850 nm LED照射、-15 V偏压下,与未掺杂ZnO纳米颗粒器件相比,亮电流密度提升了7.4倍。在此基础上,本文协同Al_(2)O_(3)界面修饰层,进一步改善器件性能。结果表明,Al_(2)O_(3)界面修饰层的插入可改善器件的阳极界面接触特性,使得器件在正向和反向偏压下都能够实现光响应。Al_(2)O_(3)修饰后的器件在15 V偏压、全光谱范围内,EQE最高可达10^(5)%,R最高达10^(4) A/W。本工作为高灵敏度有机光电探测器的发展提供了新的思路和方法。
Novel near-infrared organic photodetectors have wide application prospects in biosensing,medical imaging,and wearable electronics with the advantages of low cost,solution-spin coating,good biocompatibility,and flexible.Compared with diode organic photodetectors,high sensitive photomultiplication organic photodetectors have attracted enormous attention because of their higher external quantum efficiency(EQE>100%).The mechanism of the photomultiplication involves a type of carrier being trapped near the electrode,which assists another opposite polarity carrier tunneling into the active layer from the extra circuit.However,the performances of the device are limited by the number of traps.In this work,inorganic ZnO nanoparticles(NPs)are added into the active layer to enhance the photocurrent of the device through increasing the number of electron traps,and fortunately the dark current density of the device is maintained.It is found that the photocurrent of the device is improved by 7.4 times with optimal 5%ZnO NPs,compared with control device without ZnO NPs,under the reverse bias of-15 V,850 nm illumination.Besides,the Al_(2)O_(3)interface modification layer is further inserted into the device to improve performance of the device.The results show that the Al_(2)O_(3)based device has bi-direction response for both reverse and forward bias via changing the interface contact characteristics near anode.Ultimately,the device obtains high EQE and R up to 10^(5)%and 10^(4)A/W at a broad wavelength range of 380-1310 nm,applied with a forward bias of 15 V.This work provides a new idea and method for the development of high-sensitivity organic photodetectors.
作者
常铭茹
石林林
滑羽璐
冀婷
李国辉
许并社
董海亮
崔艳霞
CHANG Mingru;SHI Linlin;HUA Yulu;JI Ting;LI Guohui;XU Bingshe;DONG Hailiang;CUI Yanxia(College of Electronic Information and Optical Engineering,Taiyuan University of Technology,Taiyuan 030024,China;Key Laboratory of Interface Science and Engineering in Advanced Materials,Taiyuan University of Technology,Taiyuan 030024,China;College of Physics,Taiyuan University of Technology,Taiyuan 030024,China)
出处
《发光学报》
EI
CAS
CSCD
北大核心
2024年第6期986-995,共10页
Chinese Journal of Luminescence
基金
国家自然科学基金(62205235,U21A20496,62174117)
山西省重点研发计划项目(202102150101007)
山西省自然科学基金(20210302123154,20210302123169)
山西浙大新材料与化工研究院研发项目(2021SX-FR008,2022SX-TD020)
中央引导地方科技发展资金项目(YDZJSX20231A010,YDZJSX2021A012)
吕梁市人才引进专项(Rc2020206,Rc2020207)。
关键词
近红外
光电倍增
有机光电探测器
无机纳米颗粒
界面修饰
near-infrared
photomultiplication
organic photodetectors
inorganic nanoparticles
interface modification
