Ultrasensitive and high gain solution-processed perovskite photodetectors by CH3NH3PbI2.55Br0.45:Zn2SnO4 bulk heterojunction composite

Hybrid perovskite photodetectors, the novel alternative devices transform incident light into electrical signal, have been rapidly developed in the past years. However, intrinsic unbalanced charge carrier transport within hybrid perovskite materials, restricting further boosting device performance of perovskite photodetectors, has rarely been addressed. In this study, we report room temperature-operated solution-processed bulk heterojunction perovskite photodetectors with ultrahigh sensitivity and great photo-gain. It is found that the introduction of Zn2SnO4 nanoparticles into CH3NH3PbI2.55Br0.45 perovskites results in enlarged photocurrent and suppressed dark current for bulk heterojunction perovskite photodetectors. As a result, a responsivity of over 1500 mAW(-1) and projected detectivity of approximatively 10(14) Jones (1 Jones = cm Hz(1/2) W-1) from 380 to 760 nm are observed from bulk heterojunction perovskite photodetectors. In addition, bulk heterojunction perovskite photodetectors exhibit an excellent linear dynamic range of 124 dB and a great photo-gain of 535. All these results indicate that high-performance perovskite photodetectors could be realized through novel bulk heterojunction device structure.