Light-Induced Trap Reduction in Organic Shortwave Infrared Photodetectors
Light-Induced Trap Reduction in Organic Shortwave Infrared Photodetectors
复制标题
DOI：
10.1021/acsphotonics.2c01504
复制
发表时间：
2022-11
期刊：
影响因子：
7
通讯作者：
Ning Li;N. Eedugurala;J. Azoulay;T. Ng
中科院分区：
文献类型：
--
作者：
Ning Li;N. Eedugurala;J. Azoulay;T. Ng
有机电子器件中陷阱态的分布对其光电性能起着至关重要的作用。这些陷阱不仅阻碍光生载流子的传输，而且还引起严重的复合，从而恶化了检测器中的整体光响应。了解和消除有机光电探测器中的陷阱对提高和稳定响应性能至关重要。本文通过解释电荷输运动力学和阻抗特性，研究了陷阱分布对短波红外光探测器光响应性能的影响。据发现，陷阱中剩余的设备阻碍了电荷传输和收集在检测器中，因为陷阱可以作为复合中心，恶化的光响应。从电流-电压特性对电荷收集效率的分析也验证了这一假设。通过将器件适当暴露于高能光子，实现了显著的陷阱减少，这极大地改善和稳定了有机光电二极管的光响应。还观察到光诱导陷阱减少依赖于波长和光强度。这项工作的结果揭示了窄带红外传感系统的基本机制，为实际和稳定的红外传感应用设置铺平了道路。
The distribution of trap states in an organic electronic device plays a critical role in their optoelectronic performance. These traps not only hinder the transport of photogenerated carriers but also cause severe recombination, thus deteriorating the overall photoresponse in the detector. Understanding and eliminating the traps in an organic photodetector is essential to promote and stabilize the response performances. This work examines the effects of trap distribution on the photoresponse performance in a shortwave infrared light detector, by interpreting charge transport dynamics and impedance characteristics. It is found that traps remaining in the device hinder the charge transport and collection in the detector because the traps can serve as recombination centers that deteriorate the photoresponse. The analysis of charge collection efficiency from current–voltage characteristics also validates this hypothesis. A dramatic trap reduction is realized by a proper exposure of the device to high-energy photons, which largely improves and stabilizes the photoresponse of the organic photodiode. It is also observed that the light-induced trap reduction is dependent on the wavelength and light intensity. The findings in this work reveal the fundamental mechanisms in the narrow-bandgap infrared sensing systems, paving the way for practical and stable infrared sensing application settings.