Perovskite films with gradient bandgap for self-powered multiband photodetectors and spectrometers
Chuantian Zuo, Lixiu Zhang, Xiyan Pan, He Tian, Keyou Yan, Yuanhang Cheng, Zhiwen Jin, Chenyi Yi, Xiaoliang Zhang, Wu‐Qiang Wu, Qinye Bao, Liyuan Han, Liming Ding
Abstract
Bandgap-graded materials present varying spectral responses at different positions, making them possible to be used as an alternative to photoactive materials array in multi-spectral responsive devices, thus miniaturizing the apparatus. However, the preparation of bandgap-graded materials usually requires complicated deposition process. Here we report a facile low-temperature solution process to make films with lateral bandgap gradients, which form spontaneously via self-spreading and interdiffusion of solutions. We show lead halide perovskite films with MAPbCl3−MAPbBr3 and MAPbBr3−MAPbI3 gradients, which exhibit light absorption onsets ranging from 410 to 781 nm. The bandgap-graded films were used to make self-powered multiband photodetectors, which show different spectral responses at different positions without applying bias voltage. Furthermore, self-powered spectrometers were made by using the multiband photodetectors.