THE ENERGY-GAP IN A-SI1-XCX-H ALLOYS

The electronic structure of amorphous tetrahedral clusters of the type a-Si1-xCx: H are studied using the pseudopotential SCF Hartree-Fock a pproximation. The reduced energy gap is given by E-g(r)(x) similar or equal to 1 + 0.84x for x less than or equal to 0.5, whereas experiment ally E-g(r)(x) = 1 + 0.96x. For x greater than or equal to 0.5 the dip in the gap value reported experimentally is verified. (C) 1997 Publis hed by Elsevier Science B.V.