Determination of Effective Masses of Electron an Evolution of the Lattice Parameters in No Stoechiometric Cu(In1-x,Gax)Se2 Chalcopyrite Thin Film Solar Cell

In this paper, a study was carried out on the evolution of the effective mass of the electron and the effective mass of the crystal parameters in solar cells based on non-stoechiometric absorbers Cu (In1-xGax) Se2. Usually the stoechiometry is defined for this type of cells in relation to the ratio   Ga In Cu  for x between 0.1 and 0.9 with   Ga In Ga x   . For this work we have defined the stoechiometry according to the ratio   In Cu for x values between 0.1 and 0.9. We have noted that the ratio   In Cu increases with x and the energy gap Eg of the material, and that me also increases with this ratio. The lattice parameters increase with the ratio   In Cu and with the gap energy Eg. In the end, two relations linking the crystal parameters and this ratio were determined.