Abstract
In this study, the electrical and optical properties of a novel NiO-based homojunction p-i-n photodiode are reported. The p-i-n diode structure consists of Mg-doped, intrinsic and Cu-doped NiO from the top to the bottom layers, respectively. The photodiode structure was grown on a 0.7 % Nb-doped SrTiO3 (001) sub-strate using molecular beam epitaxy. The homojunction p-type NiO:Mg/i-NiO/n-type NiO:Cu exhibits diode characteristics. The ideality factor and barrier height of the diode are found to be 1.26 and 0.66 eV, re-spectively. The photoconductive properties of the photodiode were investigated by operating the diode under reverse bias, and spectral excitation of a Xe lamp. The responsivity of the photodiode is determined to be 295 mA/W at 3.9 eV. A constant photoresponse of the p-i-n photodiode between 3.75 eV and 6 eV with a responsivity of 250 mA/W is observed.