| 초록 |
Photodetectors are used in a wide range of fields such as optical communication, medical, information processing, industrial safety and precision control. Organic-inorganic perovskite materials have direct band-gap, large absorption coefficient, low exciton binding energy, long charge diffusion length, high charge carrier mobility and solution porcessability, optical-gap tenability. These properties induce high specific detectivity, large linear dynamic range and high response frequency. However, the property of low exciton binding energy can also adversely affect photodetector performance, particularly responsivity and detectivity. This property can make exciton to easily separate and induce high dark-current which makes the low responsivity and detectivity in ambient condition. We used a very thin PEI (polyethyleneimine) layer as the hole barrier layer to lower the dark current. Therefore, we can fabrication perovskite photodetectors with high responsivity and detectivity. |
