中文摘要：

用GGA＋U的方法研究了本征β-Ga2O3和Ti掺杂β-Ga2O3的电子结构和光学性能.晶格常数的计算值与实验值差别小于1％,本征β-Ga2O3的带隙计算值4.915eV,与实验值4.9eV一致.Ti替位Ga（1）位置和Ti替位Ga（2）位置的β-Ga2O3的价带最大值和导带最小值间隙分别为4.992eV和4.955eV,Ti掺杂引入的杂质带起到中间带作用,可以使电子从杂质带跃迁到导带和价带跃迁到杂质带.Ti掺杂β-Ga2O3中间带的存在使其成为潜在的宽光谱吸收太阳能电池材料.

英文摘要：

Electronic structure and optical properties of intrinsic 13-Ga2O3 and Ti-doped β-Ga2O3 were investigated by GGA＋U method. Results show that the differences between calculated lattice constants and experimental values are less than 1%, the calculated band gap of intrinsic β-Ga2O3 is 4. 915eV, which is in good agreement with experimental value of 4.9eV. Band gaps between valence band maximum and conduction band minimum in Tica（1） and Tica（2） configurations are 4. 992eV and 4. 955eV. Impurity bands introduced by Ti dopant can act as intermediate bands, which could cause electron transitions from impurity bands to conduction bands and from valence bands to impurity bands. With the existence of intermediate bands in forbidden band, Ti-doped β-Ga2O3 can enhance the utilization of sunlight for a potential solar cell material.