Determination of the band gap depth profile of the penternary Cu(In(1-X)GaX)(SYSe(1-Y))2 chalcopyrite from its composition gradient

A simple model is introduced which determines the optical band-gap energy E-g for penternary Cu(In(1-X)GaX)(SYSe(1-Y))(2) (CIGSSe) alloys from its Ga/(Ga+In) ratio as well as from its S/(S+Se) ratio. In order to verify the model the depth dependent composition of a CIGSSe sample was revealed by elastic recoil detection analysis. Applying the model, the concentration profiles were transferred in an E-g profile. Finally, these values were compared with optical band-gap energies, which were obtained directly by independent characterization methods. (C) 2004 American of Physics.