Some thoughts on the existence of empty surface states and the effect of surface order on sorption

Abstract

Experimental and computational information on the existence of empty surface bands in the upper portion of the band gap on nonpolar compound semiconductor surfaces is reviewed and it is shown that agreement is poor. However, both sources of information have reached the point where meaningful agreement can be achieved, thus presenting one of the first cases of quantitative experimental and theoretical self-consistency of the electronic properties of semiconductor surfaces. The dominant influence of surface atomic order on sorption at free nonpolar surfaces of compound semiconductors is also reviewed and it is suggested that both experimenters and theorists must incorporate this order-dependence into their work before a fundamental understanding of sorption can be achieved.