Low dark current and high-performance hybrid perovskite photodetectors with a PBDB-T:IHIC ultrathin passivation layer.

Abstract

In this Letter, the reduction of undesired high dark current caused by defect states in solution-processed perovskite for photodetectors is realized with the introduction of an ultrathin buffer layer of PBDB-T:IHIC bulk heterojunction (BHJ). By controlling the concentration of BHJ precisely during a solution process, a low dark current density (Jd) of 1.01×10-4mA/cm2 and a high specific detectivity (D∗) of 2.61×1012Jones were achieved. It was found that low Jd is attributed to the passivation effect of BHJ on defect states, where BHJ acts as a Lewis base and interacts with unbonded Pb2+ in perovskite. This Letter demonstrates that the application of ultrathin organic BHJ has significant potential for the manufacturing of high-performance optoelectronic devices.