Effect of Al and Ga codoping on the morphological, electronic, and opticalproperties of ZnO transparent conductive thin films prepared by spray pyrolysistechnique

摘要

Codoping a semiconductor thin film with two or more dopants is a feasible technique to improve the electricalproperties of the thin film. In this work, we studied the codoping of Al and Ga n-type impurities in a ZnO film (AGZO)deposited on a glass substrate by the spray pyrolysis method. The total doping concentration, [Al + Ga]/[Al + Ga +Zn], was 5 at.% with varying AlGa codoping proportions of 05, 1.253.75, 2.52.5, 3.751.25, and 50 at.%. The effectof Al/Ga codoping on the structural, texture, morphological, optical, and electrical properties of the AGZO films wereinvestigated using X-ray diffraction (XRD), atomic force microscope (AFM), scanning electron microscopy (SEM), UVvisiblespectroscopy, and four-point probe technique, respectively. Varying AlGa codoping proportions significantly alterthe textures and morphologies of the AGZO thin films. Thin films with higher Al doping content exhibit amorphouslikestructures due to fine nano grains with high concentrations of disordered grain boundary regions. The opticaltransmittance spectrums show transmittance higher than 80% in the visible light region for all the codoped films. Thesheet resistances and electrical resistivity of the AGZO films are significantly lower than those of the 5 at.% Al-dopedZnO films.