First-Principles Calculations of Electronic Structures of New III--V Semiconductors: BxGa1-xAs and TlxGa1-xAs alloys
ZHOU Jing, REN Xiao-Min, HUANG Yong-Qing, WANG Qi, HUANG Hui
Key Laboratory of Optical Communication and Lightwave Technologies (Ministry of Education), Beijing University of Posts and Telecommunications, PO Box 66, Beijing 100876
First-Principles Calculations of Electronic Structures of New III--V Semiconductors: BxGa1-xAs and TlxGa1-xAs alloys
ZHOU Jing, REN Xiao-Min, HUANG Yong-Qing, WANG Qi, HUANG Hui
Key Laboratory of Optical Communication and Lightwave Technologies (Ministry of Education), Beijing University of Posts and Telecommunications, PO Box 66, Beijing 100876
摘要We investigate the electronic structures of new semiconductor alloys BxGa1-xAs and TlxGa1-xAs, employing first-principles calculations within the density-functional theory and the generalized gradient approximation. The calculation results indicate that alloying a small Tl content with GaAs will produce larger modifications of the band structures compared to B. A careful investigation of the internal lattice structure relaxation shows that significant bond-length relaxations takes place in both the alloys, and it turns out that difference between the band-gap bowing behaviours for B and Tl stems from the different impact of atomic relaxation on the electronic structure. The relaxed structure yields electronic-structure results, which are in good agreement with the experimental data. Finally, a comparison of formation enthalpies indicates that the production TlxGa1-xAs with Tl concentration of at least 8% is possible.
Abstract：We investigate the electronic structures of new semiconductor alloys BxGa1-xAs and TlxGa1-xAs, employing first-principles calculations within the density-functional theory and the generalized gradient approximation. The calculation results indicate that alloying a small Tl content with GaAs will produce larger modifications of the band structures compared to B. A careful investigation of the internal lattice structure relaxation shows that significant bond-length relaxations takes place in both the alloys, and it turns out that difference between the band-gap bowing behaviours for B and Tl stems from the different impact of atomic relaxation on the electronic structure. The relaxed structure yields electronic-structure results, which are in good agreement with the experimental data. Finally, a comparison of formation enthalpies indicates that the production TlxGa1-xAs with Tl concentration of at least 8% is possible.
2008, Vol. 25 
