Carrier lifetime exceeding 81 ns in single crystalline perovskite nanowires enable large on-off ratio photodetectors

Abstract

Single crystalline perovskite nanowires are ideal candidates for photodetection and other optoelectronic applications due to their unique advantage of allowing the manipulation of light and carriers in nanoscale via the naturally formed boundaries. Although significant efforts have been made to grow high quality single crystalline perovskite nanowires, their carrier life times are much shorter than their bulk single crystal counterparts. Here, based on the surface initiated solution growth method with fine kinetic control, we fabricate high quality single crystalline MAPbI3 nanowires with the carrier life time as long as 81 ns, which outperforms the performances of all other solution processed single crystalline MAPbI3 nanowires. The as-prepared metal-semiconductor-metal photodetector has an extremely low dark current of 180 fA under 1 V bias, and a current of 340 pA under illumination of 10.2 mW/cm2, corresponding to an on-off current ratio of 1880, which is the largest on-off ratio in photodetectors based on MAPbI3 nanowires without any passivation treatment. Such superior performance is attributed to the long carrier life time of the as-grown MAPbI3 nanowires with reduced grain boundaries. The realized high performance MAPbI3 nanowire photodetector would find potential applications in imaging sensors.