An examination of correlation between characteristic and device performance of ZnO films as a function of La content

The aim of the study is to investigate the effect of lanthanum concentration on characteristics of ZnO films grown by chemical spray pyrolysis technique by varying doping ratios in the range, 0-5 at.% at a substrate temperature of 370 degrees C. For this purpose, microstructural, optical and electrical features of ZnO thin films were revealed as a function of lanthanum content. XRD measurements have revealed that all films had hexagonal wurtzite crystal structure without any secondary phase. Also, increase in precursor content has affected crystallization of the films as well as "a" and "c" lattice parameters and "d" spacing. It was proved by texture coefficient, standard deviation, strain and dislocation density calculation of synthesized films. Surface morphology of films has been evaluated via SEM (Scanning electron microscopy) and AFM (Atomic force microscopy) analyses and the results have supported that La content has led to mutate in surface morphology of the films. Optical properties of the films have been analysed by UV-Vis measurement. The optical band gap has been found to be connected with lanthanum doping and exhibit increasing tendency with a fluctuation. Electrical characterizations of Au/ZnO:La/n-Si heterojunction Schottky diodes have been investigated taking current-voltage (I-V) and capacitance-voltage (C-V) measurements into consideration.