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

摘要

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 (J(d)) of 1.01 x 10(-4) mA/cm(2) and a high specific detectivity (D*) of 2.61 x 10(12) Jones were achieved. It was found that low J(d) 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. (C) 2020 Optical Society of America