Electronic Structures of X Level due to Indium-Carbon Dimers in Silicon

Abstract

Electronic structures of silicon with carbon, indium, or indium-carbon dimers were calculated to investigate the interaction between indium and carbon in X center due to the indium-carbon dimers. Ab initio calculations were carried out mainly for basic Si71H60, C-Si70H60, In-Si70H60, and InC-Si69H60 clusters. The results showed that : (i) the X level was observed at EHOMO + 0.42 eV in the InC-Si69H60 which was a little bit shallower than EHOMO + 0.44 eV of the corresponding substitutional In in the In-Si70H60, (ii) dominant constituents of density of states of the X level were the partial densities of states of In and Si, and (iii) the X level had the antibonding nature between In and C.