Electroabsorption studies of organic p-i-n solar cells: Increase of the built-in voltage by higher doping concentration in the hole transport layer by Siebert-Henze, E, Lyssenko, V, Fischer, J, Tietze, M, Brueckner, R, Menke, T, Leo, K, Riede, M

Built-in voltage of organic bulk heterojuction p-i-n solar cells measured by electroabsorption spectroscopy by Siebert-Henze, E, Lyssenko, V, Fischer, J, Tietze, M, Brueckner, R, Schwarze, M, Vandewal, K, Ray, D, Riede, M, Leo, K