In this work, we investigate the influence of gallium content on the defects properties of co-evaporated CuInxGa1-xSe2 by sub gap modulated photocurrent spectroscopy and admittance spectroscopy techniques. A series of CuInxGa1-xSe2 based solar cells with different gallium content in the range from 0% to 33%, and with the same CdS buffer layer have been investigated. On one hand, photocurrent spectroscopy results show 2 types of defects named D1 and D2, and on the other hand, admittance spectroscopy results exhibit only one type of defect. I-V curves show that one of the two defects probed by photocurrent is responsible of the dominant recombination mechanisms next to the heterointerface, between the absorber and the buffer layers. Moreover, I-V curves under AM 1.5 conditions show that the cell with no probed D2 defect presents the best photovoltaic performances. (C) 2011 Elsevier B.V. All rights reserved.