Key Laboratory of Luminescence and Optical Information, Ministry of Education, Beijing Jiaotong University , Beijing 100044, People's Republic of China.
National Center for Nanoscience and Technology , Beijing 100190, People's Republic of China.
Nano Lett. 2017 Mar 8;17(3):1995-2002. doi: 10.1021/acs.nanolett.6b05418. Epub 2017 Feb 7.
Filterless narrowband response organic photodetectors (OPDs) present a great challenge due to the broad absorption range of organic semiconducting materials. The reported narrowband response OPDs also suffer from low external quantum efficiency (EQE) in the desired response window and low rejection ratio. Here, we report highly narrowband photomultiplication (PM) type OPDs based on P3HT:PCBM (100:1, wt/wt) as active layer without an optical filter. The full width at half-maximum (fwhm) of the PM-type OPDs can be well retained less than 30 nm under different biases. Meanwhile, the champion EQE and rejection ratio approach 53 500% and 2020 at -60 V bias, respectively. The small fwhm should be attributed to the sharp absorption edge of active layer with small amount of PCBM. The PM phenomenon is attributed to hole tunneling injection from the external circuit assisted by trapped electron in PCBM near the Al electrode under light illumination. These highly narrowband PM-type OPDs should have great potential applications in sensitively detecting specific wavelength light and be blind to light outside of the desired response window.
无滤光片的窄带响应有机光电探测器（OPD）由于有机半导体材料的宽吸收范围而带来了巨大的挑战。已报道的窄带响应 OPD 也存在所期望的响应窗口内的低外量子效率（EQE）和低抑制比的问题。在此，我们报告了基于 P3HT:PCBM（100:1，质量比）作为有源层的高度窄带光倍增（PM）型 OPD，而无需光学滤波器。在不同偏压下，PM 型 OPD 的全宽半最大值（fwhm）可很好地保留在小于 30nm。同时，在-60V 偏压下，冠军 EQE 和抑制比分别接近 53500%和 2020。较小的 fwhm 归因于具有少量 PCBM 的有源层的锐吸收边缘。PM 现象归因于在光照射下，外部电路辅助下的空穴从 Al 电极附近的 PCBM 中隧穿注入捕获电子。这些高度窄带 PM 型 OPD 应该在敏感检测特定波长的光方面具有巨大的应用潜力，并且对期望响应窗口之外的光不敏感。
