A new class of semiconducting materials called organic-inorganic halide perovskites hereafter could lead to commercial photoelectric devices due to the ultrahigh-performance and low cost. Meanwhile, perovskite-based photodetectors also have a rapid evolution in recent years. On the part of optical sensors, visible light detection is crucial for many applications, including imaging, medical treatment, industrial auto-control and so on. However, it is difficult for traditional preparation techniques to reach large-scale preparation accompanied by splendid performance of the device. Herein, we reported a method for high performance photodetctor by brush-coating. The device structure of the photodetector is ITO/PEDOT:PSS/CH3NH3PbI2.4Br0.6/PC61BM/C60/LiF/Ag, and the composite perovskites are consisting of CH3NH3PbI3 and CH3NH3PbBr3 with optimized mixing ratio which is crucial for not only enhancing the photon absorption but also ensuring a adjustable detection range .The device shows an excellent detectivity of ~1011 Jones under the illumination of 650 nm light at the bias of -0.5V. Due to the brush-coating process, the dark current is effectively suppressed down to 10-10 A. The present results suggest a promising strategy for fabricating outstanding perovskite-based photodetectors and provide a potential strategy for large-area fabrication.
|