title: Charge trapping in mixed organic donor-acceptor semiconductor thin films.
abstract: A pump-probe method, whereby trapped charges are optically induced to contribute to the total photocurrent, is applied to quantitatively determine the trap density in small-molecule organic semiconductor thin films and donor-acceptor blends used in organic solar cells. The trapped charge density is correlated to the cell performance, and the dependence of charge trapping on the presence of nanocrystalline domains is discussed.
authors.affiliation: Department of Electrical Engineering and Computer Science, University of Michigan, Ann Arbor, Michigan, 48109, USA; Research Center for Photovoltaic Technologies, National Institute of Advanced Industrial Science and Technology, Tsukuba, Ibaraki, 305-8568, Japan.
authors.forename: Shota
authors.initials: S
authors.lastname: Nunomura
authors.forename: Xiaozhou
authors.initials: X
authors.lastname: Che
authors.forename: Stephen R
authors.initials: SR
authors.lastname: Forrest
keywords: grain boundaries; mixed active region; nanocrystallites; solar cells