The External Crystal Structure and Electronic Structure are Simulated about Ge<sub>0.6</sub>Si<sub>0.4</sub> Quantum Dots

Abstract

The alloy Ge0.6Si0.4 quantum dots were studied by using density functional theory. The change of the electronic structure of each crystal which grown in different simulation temperature condition were investigated by molecular dynamics simulation method. The results indicate that quantum dots of silicon germanium alloy occupy the narrow band gap of each crystal face from low to high temperature conditions. Since the atomic density and crystal configuration is different, the band gap values are relatively different. The mechanism of dielectric constant transition is well explained based on the inter-band and in-band shift of band structure.