Characterization of CuIn(Ga)Se2 Thin Films

Abstract

Cu- and In-rich CuIn(Ga)Se2 thin films are investigated by magneto-optical spectroscopy in absorption and emission. These experiments reveal that the free-exciton transition is at 1.044 eV (1.5 K). The excitonic band gap was found to decrease with a slope of 7 meV/100 K between 100 and 300 K. Donor–acceptor pair recombinations located at 0.96 and 0.90 eV were found to originate from moderately deep donors in connection with shallow, effective mass-like acceptors, and deep acceptors, respectively.