Surface recombination, surface states and Fermi level pinning

Abstract

Surface and interface recombination processes, which are becoming more and more important with the appearance of small-size optoelectronic devices, are still not well understood because reliable data are very scarce. We report here the first simultaneous in situ measurements of the density and position of surface states, of the position of the Fermi level at the surface, and of the surface recombination velocity, for various treatments of the surface of InP. Classical models are shown to describe correctly the relations between those quantities. A method for engineering (reducing) the surface recombination velocity in various situations by acting on the surface states is outlined, and applications to other semiconductors such as Si and GaAs are presented