Synthesis And Characterization Of Gallium-based Semiconductor Materials Prepared By Secondary Conversion Methods

Gallium-based semiconductors have a broad application prospects in the aera of optoelectronic devices, gas sensitive materials, catalysts, sensors, phosphors etc. because of their unique physical and chemical properties. Besides chemical component, some other factors such as morphology and size of the samples also have an influence in the properties of gallium-based semiconductors to some extent. Therefore, the control of samples’ morphology and size, mechanism of samples’ growth and conversion, relationships between samples’ morphology, size and properties become hot topics in the recent researches. In this article, precursors with different morphology and size were synthesized by hydrothermal methods and their growth mechanisms were analyzed. And then, gallium-based semiconductors with different components, morphology, size and properties were synthesized through secondary conversion methods. The main research results are as follows:(1) Rod-like and particle-like GaOOH precursors with different size were synthesized by hydrothermal method, using Ga(NO3)3, polyvinyl-pyrrolidone (PVP) and NaOH as regents. The influence of precursor solution concentration, pH value, reaction temperature and PVP to samples’morphology, size and crystallization were explored in experiments, and the results showed that the pH value of precursor solution had a dominate influence in samples’morphology, size and crystallization. Therefore, the growth mechanism of GaOOH was proposed based on the pH value of precursor solution, and further, the influence of precursor solution concentration and reaction temperature in samples’state were revealed on this mechanism.(2) a-Ga2O3and P-Ga2O3semiconductors were synthesized by calcination secondary conversion method in air atmosphere, using the three kinds of preferential GaOOH precursors respectively. The all products after calcinations showed coincident morphology hereditability and different "dehydration effect". a-Ga2O3and β-Ga2O3had different Ga:O atom ratio, crystallization and photoluminescence (PL) properties when used different GaOOH precursors. The conversion properties of precursors were analyzed combining the state themselves, and further, the PL properties of samples were compared and analyzed.(3) GaN semiconductors with different morphology, crystallization and PL properties were synthesized by ammoniation secondary conversion method, using the three kinds of preferential GaOOH precursors respectively. The conversion process and properties were analyzed, and also, the PL properties of GaN semiconductors were compared and analyzed. (4) GaOOH precursors with different morphology, size and crystallization were synthesized rapidly by the microwave assisted hydrothermal method. And in this part, the experimental parameters were optimized, and then, GaOOH:Dy3+precursors with different Dy3+doping concentration were synthesized and converted into (3-Ga2O3:Dy3+phosphors which had different emission intensities and blue/yellow emission intensity ratios by calcinations in air atmosphere. Further, the PL mechanism of P-Ga2O3:Dy3+samples and Dy3+doping mechanism in GaOOH:Dy3+and β-Ga2O3:Dy3+samples discussed and analyzed.