基于反射镜光管理结构的高响应有机光电探测器

High response organic photodetector based on mirror light management structure

摘要:

与无机材料光电探测器相比，使用有机半导体材料制备的光电探测器具有制作工艺简单、易于集成、柔性好、延展性好、性能稳定等优点，但由于吸收层较薄，外部量子效率(EQE)和响应度通常较低。因此，如何利用不同的光学结构最大化有机薄膜吸收层的吸收率被广泛研究。本文成功制备出一种基于光管理结构的高响应度有机光电探测器。实验结果表明，在-10 V的偏压下，暗电流低至3.2 nA。对于有机吸收薄层，在260~980 nm波长下均具有良好的光电流响应，尤其在850 nm波长下获得了0.03 A/W响应度。与普通的有机光电探测器相比，具有光管理结构的有机光电探测器响应度显著提高了530%，比探测率增加了一个数量级，整体量子效率提高了200%。以上实验结果证明了光学增强结构对这种薄膜吸收层光电探测器的重要性，其性能尚可进一步提高，可媲美传统厚膜吸收层光电探测器。

Abstract:

Compared with inorganic material photodetectors, photodetectors prepared with organic semiconductor materials have the advantages of simple fabrication process, easy integration, good flexibility, good ductility, and stable performance. However, the External Quantum Efficiency(EQE) and responsivity are usually low due to the thin absorber layer. Therefore, how to maximize the absorptivity of organic thin-film absorber layers with different optical structures has been extensively studied. In this study, a high-response organic photodetector based on a light-management structure was successfully fabricated. The experimental results show that the dark current is as low as 3.2 nA at a bias of -10 V. For the organic absorbing thin layer, good photocurrent responses were obtained at wavelengths from 260 to 980 nm, and a responsivity of 0.03 A/W was especially obtained at 850 nm. Compared with the pristine device, the organic photodetector with the light-management structure significantly increases the responsivity by 530%, an order-of-magnitude increase in specific detectivity, and a 200% increase in overall quantum efficiency. The above experimental results prove that the optical enhancement structure is important to this thin-film absorber photodetector, and its performance can be further improved to be comparable to traditional thick-film absorber photodetectors.