A high performance Au/CH3NH3PbI3/Cu planar-type self-powered photodetector

Self-powered photodetectors are great potential candidates in the next generation of low energy-consumption photoelectric devices. However, the planar-type metal–semiconductor–metal (MSM) self-powered photodetectors (PDs) of perovskites still suffer from poor photodetection performance. Herein, by taking advantage of the spontaneous polarization property of the CH3NH3PbI3 single crystal, which can generate an extra polarization electric field, planar-type self-powered Au/CH3NH3PbI3/Cu PDs with preferable photodetection capability is reported. The resultant PDs exhibit the maximum responsivity of 0.288 A W−1 in 400–840 nm under the superposed built-in electric field by spontaneous polarization and asymmetric Schottky junction. Furthermore, the maximum detectivity is 4.69 × 1012 Jones, which is the highest record among the planar-type MSM self-powered PDs based on a perovskite. Moreover, the PDs exhibited excellent operation stability with the photocurrent of the unencapsulated photodetector remaining at 92% after 15 days in atmospheric condition.