High-Switching-Ratio Photodetectors Based on Perovskite CH3NH3PbI3 Nanowires

Hybrid organic-inorganic perovskite materials have attracted extensive attention due to their impressive performance in photovoltaic devices. One-dimensional perovskite CH3NH3PbI3nanomaterials, possessing unique structural features such as large surface-to-volume ratio, anisotropic geometry and quantum confinement, may have excellent optoelectronic properties, which could be utilized to fabricate high-performance photodetectors. However, in comparison to CH3NH3PbI3thin films, reports on the fabrication of CH3NH3PbI3nanowires for optoelectrical application are rather limited. Herein, a two-step spin-coating process has been utilized to fabricate pure-phase and single-crystalline CH3NH3PbI3nanowires on a substrate without mesoporous TiO2or Al2O3. The size and density of CH3NH3PbI3nanowires can be easily controlled by changing the PbI2precursor concentration. The as-prepared CH3NH3PbI3nanowires are utilized to fabricate photodetectors, which exhibit a fairly high switching ratio of ~600, a responsivity of 55 mA/W, and a normalized detectivity of 0.5 × 1011jones under 532 nm light illumination (40 mW/cm2) at a very low bias voltage of 0.1 V. The as-prepared perovskite CH3NH3PbI3nanowires with excellent optoelectronic properties are regarded to be a potential candidate for high-performance photodetector application.Keywords:perovskite;CH3NH3PbI3nanowires;spincoating;photodetectors