The band structure, density of states, electron density difference and optical properties of intrinsic β-Ga2O3 and N-doped β-Ga2O3 were calculated using first-principles based on density functional theory. After N d...The band structure, density of states, electron density difference and optical properties of intrinsic β-Ga2O3 and N-doped β-Ga2O3 were calculated using first-principles based on density functional theory. After N doping, the band gap decreases, shallow acceptor impurity levels are introduced over the top of the valence band and the absorption band edge is slightly red-shifted compared to that of the intrinsic one. The anisotropic optical properties are investigated by means of the complex dielectric function, which are explained by the selection rule of the band-to-band transitions. All calculation results indicate that N-doping is a very promising method to get P-type β-Ga2O3.展开更多
Using the first-principles approach based upon the density functional theory （DFT）, we have studied the electronic structure of wurtzite ZnO systems doped with C at different sites. When Zn is substituted by C, the ...Using the first-principles approach based upon the density functional theory （DFT）, we have studied the electronic structure of wurtzite ZnO systems doped with C at different sites. When Zn is substituted by C, the system turns from a direct band gap semiconductor into an indirect band gap semiconductor, and donor levels are formed. When O is substituted by C, acceptor levels are formed near the top of the valence band, and thus a p-type transformation of the system is achieved. When the two kinds of substitution coexist, the acceptor levels are compensated for all cases, which is unfavorable for the p-type transformation of the system.展开更多
Vertical p-type gallium arsenide （GaAs） nanowires with pure zinc blende structure were grown on GaAs （111） B substrate by metal-organic chemical vapor deposition via a Au-catalyst vapor-liquid-solid mechanism. The...Vertical p-type gallium arsenide （GaAs） nanowires with pure zinc blende structure were grown on GaAs （111） B substrate by metal-organic chemical vapor deposition via a Au-catalyst vapor-liquid-solid mechanism. The p-type doping was investigated by additional diethyl zinc （DEZn）. In the high Ⅱ/Ⅲ ratio range （Ⅱ/Ⅲ〉9.1%）, there exists a critical length beyond which kinking takes place. Two possible reasons are discussed. Zn occurrence in the nanowires was verified by energy dispersive X-ray （EDX） analysis. Corresponding to Ⅱ/Ⅲ = 0.2%, the doping concentration is about 8 × 10^18 cm^-3.展开更多
基金supported by the Natural Science Foundation of Shaanxi Province,China (2009JM8013)Northwest University Graduate Innovation and Creativity Funds,China (08YZZ47)~~
基金supported by the National Natural Science Foundation of China (Grant No. 10974077)the Natural Science Foundation of Shandong Province, China (Grant No. 2009ZRB01702)the Project of Shandong Province Higher Educational Science and Technology Program (Grant No. J10LA08)
文摘The band structure, density of states, electron density difference and optical properties of intrinsic β-Ga2O3 and N-doped β-Ga2O3 were calculated using first-principles based on density functional theory. After N doping, the band gap decreases, shallow acceptor impurity levels are introduced over the top of the valence band and the absorption band edge is slightly red-shifted compared to that of the intrinsic one. The anisotropic optical properties are investigated by means of the complex dielectric function, which are explained by the selection rule of the band-to-band transitions. All calculation results indicate that N-doping is a very promising method to get P-type β-Ga2O3.
基金supported by the National Natural Science Foundation of China(No.10775088)the Key Program of Theoretical Physics of Shandong Province
文摘Using the first-principles approach based upon the density functional theory （DFT）, we have studied the electronic structure of wurtzite ZnO systems doped with C at different sites. When Zn is substituted by C, the system turns from a direct band gap semiconductor into an indirect band gap semiconductor, and donor levels are formed. When O is substituted by C, acceptor levels are formed near the top of the valence band, and thus a p-type transformation of the system is achieved. When the two kinds of substitution coexist, the acceptor levels are compensated for all cases, which is unfavorable for the p-type transformation of the system.
基金supported by the National Natural Science Foundation of China(52162029)Yunnan Provincial Natural Science Key Fund(202101AS070015)+1 种基金the National Key R&D Program of China(2022YFF0503804)the Outstanding Youth Fund of Yunnan Province(202201AV070005)。
基金Project supported by the National Basic Research Program of China(No.2010CB327601)the Key International Cooperation Research Project of the National Natural Science Foundation of China(No.90201035)+2 种基金the Chinese Universities Scientific Fund(No. BUPT2009RC0410)the National Natural Science Foundation of China(No.61077049)the 111 Program of China(No.B07005).
文摘Vertical p-type gallium arsenide （GaAs） nanowires with pure zinc blende structure were grown on GaAs （111） B substrate by metal-organic chemical vapor deposition via a Au-catalyst vapor-liquid-solid mechanism. The p-type doping was investigated by additional diethyl zinc （DEZn）. In the high Ⅱ/Ⅲ ratio range （Ⅱ/Ⅲ〉9.1%）, there exists a critical length beyond which kinking takes place. Two possible reasons are discussed. Zn occurrence in the nanowires was verified by energy dispersive X-ray （EDX） analysis. Corresponding to Ⅱ/Ⅲ = 0.2%, the doping concentration is about 8 × 10^18 cm^-3.
