Density Functional Investigation of Phase Transition in Silicon Nanomembranes

Silicon is an important material at the center of the microelectronic systems industry, and nanomembranes of silicon have a wide range of material, mechanical, optical, and device applications. Recent experimental advances have achieved nanometer-scale flatness, and membrane properties have been found to depend directly on thickness. Using an atomistic slab model, we simulate the electrons with density functional theory in order to investigate the pressure phase transition of silicon in the membrane from semiconducting diamond phase to metallic beta-tin phase. We vary exchange-correlation approximation, comparing to bulk values in each approximation, and we calculate the electronic and vibrational properties of the membranes.