Effects of Dopants on Electronic Surface States in InAs

The effects of several adatom dopants (H, Be, C, N, Si, and Zn) on the electronic structure of low-energy surface reconstructions of InAs-(001, 110, 111, and 112) low-index planes-were investigated using ab initio density functional theory calculations. It was observed that the local electronic structure can be controlled in such materials, either reducing or enhancing surface states depending on the dopant and the unique surface reconstruction. The local bonding environment, in particular whether the bonding has an aromatic character, was found to influence both surface reconstruction and a dopant's affinity for a surface. Beryllium and Zinc were often found to reduce the surface states around the band gap, which could improve the charge-carrier mobility in various electronic components. However, these dopants can also cause further surface reconstruction/reconfiguration inducing different surface states.