Optimization of erbium percentage molarity on cobalt selenide semiconductor material via spray pyrolysis deposition technique for photovoltaic application

Abstract

The spray pyrolysis approach was used to successfully synthesize cobalt selenide (CoSe) and cobalt selenide doped erbium (CoSe/Er) materials. The XRD patterns of cobalt selenide (CoSe) and cobalt selenide doped erbium (CoSe/Er) semiconductor materials show strong crystalline peaks at 2θ = 16.03°, 20.29°, 23.89°, 31.92°, and 41.32°, corresponding to diffraction planes (110), (111), (200), (203), and (220). The formation of cobalt selenide material can be determined from the X-ray spectrum angle 16.03°, which corresponds to diffraction plane (110) while the remaining 2 theta angles and diffraction peak demonstrate the formation of cobalt selenide doped erbium. The average size of the crystallites was calculated to be 55.08 nm. Surface morphology analyses indicated homogenous flat nanocrystals at low doping concentrations and massive nanocrystal clusters as doping concentrations increased. The transmittance spectra show that the transmittance of both the CoSe and the Er-doped CoSe thin films significantly increases below 400 nm. The estimated direct bandgap, which is in the 1.53–2.01 eV range and rises with concentration due to a strong quantum effect, makes it appropriate for use in photovoltaic cells.