Redetermination of the valley-orbit (chemical) splitting of the 1s ground state of group-V donors in silicon.

Abstract

The sixfold degeneracy of the 1s(A 1 +E+T 2 ) ground state of substitutional group-V donors in Si, originating from the six Δ conduction-band minima, is lifted by the valley-orbit (chemical) splitting, with 1s (E) and 1s(T 2 ) remaining close to the effective-mass position and 1s (A 1 ) depressed significantly. The binding energies of 1s(A 1 ), 1s (E), and 1s(T 2 ) are accessible to an experimental determination through the observation ofthe 1s(A 1 ), 1s (E), 1s (T 2 )→np 0 ,np± transitions in the Lyman spectrum of the neutral donors, where the p 0 and p ± levels are accurately described in the effective-mass theory