In-situ monitoring of surface chemistry and charge transfer at semiconductor surfaces

A simple method for in-situ distinction between the effect of dipole formation/annihilation and charge transfer to/from surface gap states on the semiconductor work function is described. The technique is based on simultaneous monitoring of the work function and photovoltage at the semiconductor surface. The approach is illustrated by experiments performed on single crystalline InP(100) surfaces and polycrystalline Cu(In,Ga)Se2.