High-gain broadband organolead trihalide perovskite photodetector based on a bipolar heterojunction phototransistor

With organolead trihalide perovskite CH3NH3PbI3 films serves as Base layer, the first perovskite photodetector based on bipolar heterojunction phototransistor structure is demonstrated. Due to the large absorption coefficients and very long diffusion lengths of perovskite film, the device has a broad response from 360 to 820 nm and photoresponsivity reaches 125 A/W, its EQE is as high as 3.62 × 104% at the wavelength of 427 nm.229