Ultrafast bi-excitonic dynamics and annihilation in molecular and mesoscopic systems Pavel Malevich, Constantin Heshmatpour, Craig N. Lincoln, Harald Ceymann, Maximilian H. Schreck and Jürgen Hauer EPJ Web Conf., 205 (2019) 06013 Published online: 16 April 2019 DOI: 10.1051/epjconf/201920506013