A model for the open circuit voltage relaxation in Cu(In,Ga)Se2 heterojunction solar cells Th. Meyer, M. Schmidt, F. Engelhardt, J. Parisi and U. Rau Eur. Phys. J. AP, 8 1 (1999) 43-52 Published online: 15 October 1999 DOI: 10.1051/epjap:1999228