Density-functional calculation of sub-band structure in accumulation and inversion layers

Abstract

The Hohenberg-Kohn-Sham theory of an inhomogeneous electron gas is applied to the calculation of the subband structure of accumulation and inversion layers on the Si (100) surface. The exchange-correlation effect is shown to be very important and lower the sub-band energies considerably. Especially in accumulation layers the first excited sub-band really becomes a bound state in contrast to the result of the Hartree approximation. The agreement between the theory and experimental results of inter-sub-band optical transitions is satisfactory. The effective mass and the $g$ factor are also calculated.