Research On The Relationship Between Structure And Properties Of Gallium Oxide Heteroepitaxial Film

In recent years, the solar blind UV detection technology has little background noise advantages, more and more research institutions concerned it around the world, the sensitive materials of solar blind UV have AlGaN, ZnMgO and diamond. In recent years, people have come to realize: the gallium o xide is wide band gap semiconductor material and a direct band gap, the band gap of about 4.9 eV, is very suitable for the development needs of solar blind ultraviolet detectors, however, gallium oxide material Research is just beginning, the relationship between the gallium oxide film heteroepitaxial microstructure between its UV detector has not been fully understood, this paper through a variety of technical means to control the microstructure of heteroepitaxial gallium oxide film, and through the photoconductive Development and performance measurement type solar blind UV detectors, trying to heteroepitaxial gallium oxide film microstructure and its photoconductive properties linked to the main contents of the whole paper is divided into the following sections:（1） Carried out a study of polycrystalline gallium oxide thin- film photovoltaic characteristics under different atmosphere and a different temperature annealing on the gallium oxide film microstructure and photoconductive properties, using XRD, AFM and other means to characterize the annealing treatment on Effect of gallium oxide film microstructure, microstructure test showed that: in either annealing atmosphere conditions, gallium oxide film quality as the annealing temperature will gradually changed for the better, when the annealing temperature reaches 1050 ℃, prepared gallium oxide film having a（2_<sub>01） preferential orientation feature. In addition, gallium oxide thin films prepared under different conditions annealed solar blind ultraviolet photoconductive detectors, the device test results showed that: In either annealing atmosphere conditions, will be with the annealing temperature, the light detector dark current gradually decreased, the response time of the device is deteriorated, however, light and dark current than the device will rise at a temperature of 104 to achieve an order of magnitude, and UV spectral response curve exhibits a blue shift phenomenon, the cutoff wavelength gradually decreases（2） To carry out the vapor phase growth structure and properties of epitaxial gallium oxide film microstructure was studied in situ annealing the substrate on the gallium oxide film microstructure and photoconductive properties, the results show: a substrate in situ annealing of β-Ga₂O₃ film crystalline quality has improved to some extent, with the extension of the substrate in situ annealing time, β-Ga₂O₃ thin- film crystal quality will become better at first and then gradually worse, when the substrate in situ annealing time of 60 min, β-Ga₂O₃ thin-film crystal best quality, while the substrate in situ annealing time of 240 min, β-Ga₂O₃ thin- film crystal quality is the worst. In addition, the device also found that by preparing experiments: vapor phase epitaxy gallium oxide film the better the quality, the higher the conductivity of the film, photoconductive detectors of light and dark current increases, but the shorter the rise time of the device decreases the longer the time.（3） Carried out in different orientations sapphire substrate vapor phase epitaxial growth of thin films of gallium oxide, using XRD, SEM and other means to characterize the microstructure of gallium oxide films prepared microscopic test results show that: in the r-plane sapphire substrate epitaxial growth the β-Ga₂O₃ film having a（001） preferential orientation feature film surface smooth dense grain boundaries significantly, showing a good crystalline quality. The growth of β-Ga₂O₃ film prepared device, the device test results showed that: photocurrent of the device up to 2.5 μA, light and dark current ratio as high as 105, the rise time of the device is only 1.24 s, in addition, ultraviolet spectral response curve display: UV cut-off wavelength of the device 280 nm, and the maximum ratio of the optical response of the optical response of the 280 nm reaches three orders of magnitude, showing extremely excellent solar blind UV response.