【摘要】 识别光信号的波长在生物医学传感、机器视觉及图像处理等方向都有极大的应用价值。传统的方式是由光学滤波片或光谱仪对宽带光谱进行滤波或分光,再结合宽带光电探测器件检测,从而实现对波长的鉴别。但这种实现方式的成本高、系统体积大。为了解决这一问题,文中提出一种基于二维钙钛矿材料的窄带光电探测器,它无需任何额外光学元件,也能够实现对光波长的鉴别功能。该探测器的光谱响应峰在552nm处,其峰值半高宽仅为22 nm,峰值的响应度达到0.55A/W,对应的外量子效率为124%。探测器的比探测率高达3.5×10¹¹ Jones,暗电流低至10^-13A,开光比为10³。这种高性能的窄带探测可归因于材料内存在的自陷态激子的辅助吸收作用及各向异性的电导率对于窄带电荷收集的促进作用。更多还原

【Abstract】 Narrowband photodetectors play an important role in biomedical sensing, machine vision and image processing. Traditionally, the optical filter or spectrometer is used to select narrowband spectrum to realize color discrimination. In order to reduce the cost and simplify the system, a two-dimensional perovskite based narrowband photodetector without any additional optical element is proposed. The results show that there is only one narrow single response peak at 552 nm with the full width at half maximum of only 22 nm. The device exhibits a responsivity of 0.55 A/W, an external quantum efficiency of 124%, a specific detectivity of 3.5×10¹¹ Jones at 552 nm. In addition, the dark current is as low as 10^-13A and the on-off ratio can reach 10³. We attribute such excellent performances of the device to the enhanced self-trapped states below the bandgap and the low electrical conductivity in the out-of-plane direction, which assist the charge collection narrowing.更多还原