A comparative study of the electronic band structures of hydrogen-terminated silicon chains by density functional theory with and without GW correction

A comparative study of the electronic band structures of hydrogen-terminated silicon atomic chains with < 110 > and < 112 > orientations was conducted using density functional theory (DFT) both with and without GW correction. A direct band gap was revealed in the < 110 > chain and an indirect band gap was revealed in the < 112 > chain. The same order of the energy levels at specific k points was observed with both levels of theory. The GW correction to the energy difference of the conduction band minima at points Gamma and X was within 0.16 eV and does not change the order of energy levels. This study supports the validity of DFT for the qualitative determination of electronic band structures of low-dimensional hydrogen-terminated silicon systems. (C) 2007 Elsevier Ltd. All rights reserved.