Preparation and Characterization of Nanostructured Inorganic Copper Zinc Tin Sulfide-Delafossite Nano/Micro Composite as a Novel Photodetector with High Efficiency

Abstract

A novel photodetector, based on Cu2ZnSnS4, CZTS, is deposited on Cu/CuFeO2 for wavelength and light power intensity detection. The preparation of CuFeO2 is carried out by the direct combustion of Cu foil wetted with Fe(NO3)2 solution. The preparation of CZTS is carried out using the hydrothermal method, then it is dropped on CuFeO2 using the drop casting method at 70 °C. Various analyses are used to look at the chemical, morphological, and optical aspects of the Cu/CuFeO2/CZTS, such as UV–vis, SEM, TEM, selected-area electron diffraction, and XRD, in which all characteristic peaks are confirmed for the prepared materials. The Cu/CuFeO2/CZTS thin film’s SEM image has a homogeneous morphology, with particles that are around 350 nm in size, demonstrating a significant improvement in morphology over Cu/CuFeO2/CZTS thin film. The TEM analysis verified the nanostructured morphology of Cu/CuFeO2/CZTS. From XRD analysis of Cu/CuFeO2/CZTS, the high intensity of the generated peaks indexed to hexagonal (2H) CuFeO2 and kesterite CZTS crystal structures revealed a compact highly crystal material. From optical analysis, CZTS, Cu/CuFeO2, and Cu/CuFeO2/CZTS thin films recoded band gaps of 1.49, 1.75, and 1.23 eV, respectively. According to the band gap measurements, the optical absorption of the Cu/CuFeO2/CZTS photodetector has clearly increased. The Cu/CuFeO2/CZTS as photodetector has a detectivity (D) and responsivity (R) of 1.7 × 1010 Jones and 127 mAW−1, respectively. Moreover, the external quantum efficiency (EQE) is 41.5% at 25 mW·cm−2 and 390 nm. Hence, the prepared Cu/CuFeO2/CZTS photodetector has a very high photoelectrical response, making it very promising as a broadband photodetector.

Keywords

• photodetector
• Cu/CuFeO₂/CZTS
• lead-free inorganic
• band gap
• detectivity
• responsivity