光子学报, 2018, 47 (10): 1004002, 网络出版: 2018-12-18
低电压倍增型高比探测率蓝光有机光电探测器
High Detectivity Blue-light Organic Photodetectors with Photomultiplication at Low Voltage
有机光电探测器 光电倍增 电子陷阱 空穴隧穿注入 比探测率 Organic photodetectors Photomultiplication Electron trap Hole tunneling injection Detectivity
摘要
选取光电倍增结构探测器, 在聚(3-己基噻吩)(P3HT)∶[6,6]-苯基-C61-丁酸甲酯(PC61BM)中掺入小比例碳60(C60)作电子陷阱, 研究了在陷阱辅助作用下引入阴极空穴隧穿注入产生光电倍增的机理以及C60浓度对器件光电性能的影响.当电子陷阱C60浓度为1.5 wt.%时, -0.5 V偏压下探测器在波长为455 nm、光功率为0.21 mW·cm-2光照下外量子效率为436.4%, 响应度为1.62 A·W-1, 比探测率为2.21×1013 Jones, 线性动态范围约为100 dB.光照下部分光生电子被活性层中的陷阱俘获, 特别是在靠近阴极Al处的电子积累, 将诱导阴极空穴隧穿注入, 结合利用体异质结探测器低工作电压的优势, 可大幅提高光电流, 从而获得低工作电压、高比探测率的探测器.
Abstract
Photomultiplication structure that introduces a small proportion of C60([60]Fullerene) as electron traps into P3HT(Poly(3-hexylthiophene))∶PC61BM([6,6]-Phenyl-C61-butyric acid methyl ester) was applied to organic photodetectors. The photomultiplication mechanism based on trap assisted hole tunneling injection and the role of C60 concentration on device photoelectric performances were investigated. When the C60 doping concentration was 1.5wt.%, the resulting photodetector exhibits a 436.4% external quantum efficiency, a 1.62 A·W-1 responsivity, a 2.21×1013Jones detectivity and about 100 dB linear dynamic range at -0.5 V under 455 nm (0.21 mW·cm-2) illumination. The advantage of bulk heterojunction photodetectors that can operate under low bias, combined with the cathode hole tunneling injection which originates from some photoinduced electrons trapped in the active layer especially for the accumulation of electrons near the cathode, was utilized to improve light current dramatically. Thus the photodetector with high detectivity and low operating voltage was obtained.
安涛, 龚伟, 刘欣颖. 低电压倍增型高比探测率蓝光有机光电探测器[J]. 光子学报, 2018, 47(10): 1004002. AN Tao, GONG Wei, LIU Xin-ying. High Detectivity Blue-light Organic Photodetectors with Photomultiplication at Low Voltage[J]. ACTA PHOTONICA SINICA, 2018, 47(10): 1004002.