Effect of Cd-doping on optoelectronic properties of ZnO thin films and their application for MAPbI ₃ photodetector

Abstract The Sol–gel method was used to synthesize Cd-doped ZnO nanoparticles at different doping concentrations. The nanomaterials crystal structure and microstructure were explained by XRD and SEM analysis of the materials. The absorption and transmission spectra were analyzed to explore the optical properties of Cd-doped ZnO thin films. The band gap of nanomaterials decreases from 3.26 to 3.12 eV with the increase of Cd doping concentration in ZnO. The Cd-doped ZnO shows an increasing trend of electrical conductivity and mobility with the increase of Cd concentration in ZnO. The Cd-doped ZnO-based MAPbI 3 photodetectors show substantial responsivity in the wavelength range of 365 to 635 nm. The highest responsivity for devices FTO/ Zn 1-x Cd x O/MAPbI 3 /Al, having x = 0.05, 0.10 and 0.15, upon 465 nm wavelength (4 mW cm −2 ) illumination are ∼0.192, 0.272, and 2.1 μA W −1 , respectively. The LDR of the x = 0.15 Cd-doped ZnO photodetector is two times higher than the x = 0.05 concentration of Cd doped ZnO photodetectors. Our studies confirm that the Cd-doped ZnO creates band narrowing and may be used for suitable perovskite photodetector.