Optoelectronic and electrochemical behaviour of γ-CuI thin films prepared by solid iodination process

A simple and efficient solid iodination method has been proposed for the fabrication of p-type γ-CuI thin films. The structural, morphological, optical, electrical and electrochemical properties have been investigated in order to serve as an effective hole-transporting layer in solid-state solar cells. The fabricated films exhibited p-type conductivity with resistivity of 7.0 × 10−2 Ω cm, the hole concentration of ~1.13 × 1019 cm−3 and the mobility of 18.34 cm−2 V−1 s−1. The cyclic voltammetry result shows a maximum specific capacitance of 43 mF/cm2 at a scan rate of 10 mV/s. The cyclic stability and capacitance retention were found to be 99.7%. These findings demonstrate that γ-CuI film can be a potential candidate for multiple applications, such as a hole transporting material for solid-state solar cells and electrochemical supercapacitor. [Display omitted] •p-Type γ-CuI thin films were successfully fabricated by solid-iodination method.•Optoelectronic and electrochemical properties of γ-CuI thin films were studied.•High mobility (18.34 cm−2 V−1 s−1) with carrier concentration (~1.13 × 1019 cm−3).•Maximum specific capacitance of 43 mF/cm2 was achieved at scan rate of 10 mV/s.•The cyclic stability and capacitance retention was found to be 99.7%.