Effect of rare earth Pr doping on core characteristics of electrodeposited nanocrystalline Cu2O films: a film for optoelectronic technology

Undoped and Pr doped Cu2O nanocrystalline films were fabricated by the electrodeposition method. These films were studied to investigate the formation, morphology, optical, and photoresponse properties on Pr doping concentrations (i.e., 0, 1, 3, and 5 wt%). Structural studies of the deposited Cu2O:Pr films exposed the cubic crystal structure with polycrystalline nature. The crystallite size is decreased from 54 to 29 nm by increasing the Pr doping concentrations. The Raman peaks at 110, 147, 215, 413, and 633 confirm the Cu2O phase and well matched with the XRD results. The morphological study shows that the pyramid-shaped particles are homogeneously arranged on the film surfaces. The absorption is high for the film deposited with the 5% Pr doping is due to the maximum thickness than the other films. The calculated band gap values of Cu2O:Pr films were reduced from 2.06 to 1.90 eV with raising the Pr doping level. PL spectra showed high intense emission peak at 617 nm which confirms the NBE emission of Cu2O lattice. Index of refraction (n) and coefficient of extinction (k) values were increased on increasing the doping concentration from 0 to 5%. From photosensitivity analysis, there is an increase of photoresponse behavior with respect to illuminated current.