Investigation was performed on chalcopyrite materials of solar cell absorbers, Cu(In,Al)Se2, to observed the CuInSe2 structural modification by Al addition. The investigation was done by Cu(In,Al)Se2 preparation, i.e. pulsed laser deposition and selenization, and characterization, i.e. film composition, structure, and morphology. The Al composition of the films was varied, i.e. 0, 3.8%, 8.2%, 11.3%, 16.6, and 25.6% of [Al]/[In + Al]. The results show that Al can be used for In substitution in CuInSe2 and keeping the chalcopyrite structure. In tetragonal of Cu(In,Al)Se2 chalcopyrite, the Al addition modifies the lattice parameter c, where the more Al addition to CuInSe2, the lattice parameter c will be shorter, revealing that the Al substitutes In in the parallel line of c-axis that causes the compressed tetragonal configuration. By this, the structure of thin film absorber based on CuInSe2 chalcopyrite can be modified by Al addition for a good solar cell application.

Keywords: Structural modification, Cu(In,Al)Se2, Solar cell.