Thickness dependence of photoluminescence-decay profiles of exciton-exciton scattering in ZnO thin filmsShuji Wakaiki, Hideki Ichida, Toshiki Kawase, Kohji Mizoguchi, DaeGwi Kim, Masaaki Nakayama and Yasuo KanematsuEur. Phys. J. B, 86 9 (2013) 387DOI: https://doi.org/10.1140/epjb/e2013-30631-5