A high-performance self-powered broadband photodetector based on a CH₃NH₃PbI₃ perovskite/ZnO nanorod array heterostructure

Here we report a self-powered photodetector based on a ZnO/CH₃NH₃PbI₃ heterojunction and a MoO₃ hole-transport layer. The organolead iodide perovskite photodetector is sensitive to broadband wavelengths from the ultraviolet light to the entire visible light region (250-800 nm), showing a high photo-responsivity of 24.3 A W^-1 and a high detectivity value of 3.56 × 10¹⁴ cm Hz^1/2 W^-1 at 500 nm without external bias voltage. Meanwhile, we found that the photodetective performances are closely related to the thickness of the MoO₃ layer, which acts as a hole-transport layer and an electron-blocking layer and can effectively decrease the recombination of holes and electrons. Additionally, the as-fabricated photodetector exhibits good stability and only 9.3% photoelectric response current decay after a 3-month illumination test. The high detectivity and responsivity of such a ZnO nanorod/perovskite heterojunction are clearly demonstrated and should be widely applicable to other photoelectric detection devices.