Electronic structure calculation of Yttrium doped α-alumina using density functional theory

Ab Initio calculations is a valuable means in understanding the characters of materials at atomic scale without the input of empirical data. This is especially important at the early stage of research when decision need to be made on the selection of elemental combinations of the materials studied and to reduce both experimental cost and time. In determining ground-state electronic properties, density functional theory (DFT) has been proved to be very predictively accurate. In this paper, we explore the usage of DFT in our investigation to find high-k materials for replacing SiO2 as gate dielectric in metal oxides semiconductor devices (MOS) focusing on alumina based system. DFT is used to calculate the electronic structures of a-alumina doped with yttrium. Yttrium is substituted at the octahedral Al sites in the a-alumina system and calculation were performed using the gradual gradient approximation approach. The bandgap and density of states profiles of pure and doped a-alumina were discussed. (Author)