Electronic structure of insulator-confined ultra-thin Si channels

We consider ultra-thin Si channels terminated with (001) surfaces and confined by insulating media and discuss the dependence of the Si electronic structure on the channel thickness. We consider two types of the structural models: a vacuum-confined Si slab with the dangling bonds terminated by H atoms and a slab confined by α-quartz. The results of our ab initio calculations carried out using a periodic model and the PBE density functional demonstrate that both the band gap and the effective mass of Si slabs depends on the slab thickness and strongly suggest that this dependence should be taken into account in the device modeling.