Doping dependence of electronic and mechanical properties of GaSe1-xTex and Ga1-xInxSe from first principles

作者:Rak Zs*; Mahanti S D; Mandal Krishna C; Fernelius N C
来源:Physical Review B, 2010, 82(15): 155203.
DOI:10.1103/PhysRevB.82.155203

摘要

The electronic and mechanical properties of the hexagonal, layered GaSe doped with Te and In have been studied using first-principles pseudopotential method within density-functional theory. The calculated elastic constants of the end compounds GaSe and InSe compare well with the available experimental and theoretical values. As we go from GaSe to InSe, the elastic constants C-13, C-33, and C-44 increase while C-11 and C-12 decrease, suggesting that the crystal becomes stiffer in the direction perpendicular to the atomic layers and the softer in the direction parallel to the layers, as more substitutional In is incorporated in GaSe. The electronic structure and the formation energies of several defects and simple defect complexes are discussed and the calculated charge transition levels are compared to available experimental data. We demonstrate that In doping may play an important role in the observed enhancement in the structural properties of GaSe. Depending on the Fermi energy, In can either substitute for Ga (In-Ga) or occupy an interstitial position as a triply charged defect (In-i(3+)). While the substitutional In does not change significantly the electronic and mechanical properties of the host, we find that the shear stiffness of GaSe is considerably increased when In is incorporated as charged interstitial impurity.

  • 出版日期2010-10-12