Solution-Processed CuI-Based Semiconductor Films Deposited on Mica Substrate for Flexible UV Photodetector Application

The CuI and CuI:Zn semiconductor films and MSM-structured UV photodetectors were fabricated on flexible mica substrates by a low-temperature solution process. Both CuI-based films exhibited a polycrystalline phase and an optical bandgap energy close to 3.0 eV. Hall effect measurement showed that the CuI sample exhibited p-type conductivity and the CuI:Zn sample n-type conductivity, the latter having a higher carrier mobility of 17.74 cm
²
/V s. The I-V curves of the two kinds of photodetectors showed asymmetric rectification characteristics. The CuI:Zn devices exhibited significantly better sensitivity, responsivity, and specific detectivity than those of the CuI devices. It was found that the optoelectronic performance of flexible CuI -based photodetectors would degrade under the application of tensile stress by bending test.