Electrosynthesis And Characterization Of Nano Gallium Arsenide Thin Films By Electrodeposition Method

Gallium arsenide (GaAs, Eg=1.42eV (300K)), was an important III-V group direct band gap compound semiconductor optoelectronic materials with high electron mobility, semiconductor characterization, and optical and electrical properties, which was also one of the most important and basic materials of the current development in high-power electronic devices. It was concerned by domestic and foreign researchers, and widely used in microwave and high-speed devices, the photovoltaic field and satellite data transmission, telecommunications, military and other fields.There were many methods to get preparation of GaAs material in industrial. Electrodeposition which was generally used by different means (including constant voltage electrodeposition method, constant current electrodeposition method, pulse current deposition method, pulsed voltage deposition method, etc) to improve the cathode polarization (including the influence of different the ratio of precursor solution concentration and pH value, different substrates and different complexing agents on experiment). Constant voltage deposition and pulsed current deposition were adopted in this article, metal Ga and As2O3was used as raw materials, nano-scale GaAs thin film materials was prepared in the acidic precursor solution, and its morphology, stoichiometric ratio and the optical properties were analyzed systematically, and the main findings were as follows:1. Used chemical CV method, by different means of characterization, we analyzed electrochemical synthesis of principles of GaAs films, and investigated the influence of stoichiometric ratio of Ga and As, precursor solution pH value, deposition voltage value, as well as annealing temperature and time on the formation of the GaAs film in the synthesis of GaAs thin film experiments at room temperature under electrochemical constant pressure condition, and made a detailed analysis of the optical properties of the films at the same time.2The GaAs film which was prepared by constant voltage method was characteristic of large particles and poor uniformity, which affect the flatness of the film. Therefore, GaAs film in our research was synthetized with the pulse current deposition method, by the use of a complexing agent EDTA. Considering the effect of the complexing agent, the duty cycle of the pulse current, peak current density, the influence of the annealing conditions on the Ga and As atomic ratio, and the impact of the GaAs film morphology, the optimal parameters of the pulse electrodeposited GaAs films was obtained, meanwhile the optical properties of the GaAs film was studied.