High-Performance Perovskite Dual-Band Photodetectors for Potential Applications in Visible Light Communication

Due to the rapid development of smart technology infusion, visible light communication (VLC) has been promising as a connection belt among real estates due to the appealing features including fast speed of data transmission and high bandwidth. Unfortunately, the issues of crosstalk, interference, or data leakage in the VLC impose rigorous requests for the receiver terminal, photodetector, including fast and accurate signal recognition, rapid decoding, etc. In pursuit of distinctive merits, a dual-band photodetector is proposed as an efficient receiver terminal for VLC in this work. With MAPbBr₃ and MAPbI₃ as photoactive layers, a device by stacking two photodiodes in opposite polarity is constructed to sense the signals at two different wavelengths from a commercial white light-emitting diode (LED) transmitter. By manipulating the applied bias direction, the response of a single device can be controllably switched between 300-570 and 630-800 nm with an optical crosstalk of less than -30 dB. The performance with an I_on/I_off ratio of about 10⁸, a response bandwidth (f_-3dB) of ∼33 kHz, a response switching rate approaching 1000 Hz, and a detectivity of 1.75 × 10¹⁰ Jones ensures its application as an efficient data receiver. We believe that this work will provide the motivation to explore novel functional perovskite optoelectronic devices and put them to practical applications in the special field.