[1] Aalto Univ, Dept Appl Phys, New Energy Technol Grp, PO Box 15100 Aalto, Espoo 00076, Finland
[2] Solaronix SA, Rue Ouriette 129, CH-1170 Aubonne, Switzerland
[3] Aalto Univ, Sch Chem Technol, Dept Forest Prod Technol, Espoo, Finland
[4] Tampere Univ Technol, Dept Chem & Bioengn, FIN-33101 Tampere, Finland
[5] VTT Tech Res Ctr Finland, PO Box 1000, FIN-02150 Espoo, Finland
[6] Ecole Polytech Fed Lausanne EPFL, Lab Photon & Interfaces, CH G1 551,Stn 6, CH-1015 Lausanne, Switzerland