The authors have made photoluminescence intensity (PLI) measurements on thin GaAs and InGaAs films to compare the surface recombination velocity at interfaces of the materials with AlAs and native oxide. An analytical expression for the internal quantum efficiency of the PLI method for thin semiconducting films is derived. This expression is applied to measurements on specially designed multilayer structures based on GaAs and InGaAs thin films. The results show that the native oxide on an In0.15Ga0.85As film has a one order of magnitude lower surface recombination velocity than the native oxide on a GaAs film. (c) 2007 American Institute of Physics.