“The impact of molecular orientation on the photovoltaic properties of a phthalocyanine/fullerene heterojunction,” B.P. Rand, D. Cheyns, K. Vasseur, N.C. Giebink, S. Mothy, Y. Yi, V. Coropceanu, D. Beljonne, J. Cornil, J.-L. Bredas, J. Genoe, Adv. Funct. Mater., 22, 2987 (2012).