S.V. CHERTOPALOV, V.V. BRUEVICH, A.A.GROMCHENKO, D.U. PARASCHUK
The dependence of current- voltage characteristics poly[3-hexylthiophene] (P3HT) composite and highly soluble methan-fulleren C60 PCBM bulky heterojunction based fullerene polymer photocells upon upper electrode material has been analyzed. Fullerene polymer photocell samples were made on transparent conductive ITO films, that were deposited on a glass surface with 50 nm thick intermediate layer of water solution polymer blend. Then the poly[3-hexylthiophene-2,5-diyl] (P3HT) polymer and fullerene PCBM solution was deposited over composite P3HT/PCBM layer by means of centrifuging. Upper metal electrode of Al, CaAl, Yb, Au was deposited in vacuum. Fine polycrystal films with crystallite size of 10nm for Al, 20nm for CaAl and 50-90nm for Yb were obtained while metal electrode depositing. The composite film structure photocurrent due to photon absorption in an active P3HT/PCBM layer was studied. As a result of photon absorption an exciton appears, that dissociates at donor and accepter border. Then the electron and the hole transfer through accepter to the metal and polymer electrode accordingly. The obtained photosells based on P3HT/PCBM composite with Yb electrode have demonstrated the efficiency about 0.84% at open-circuit potential about 0.48 V, CaAl upper electrode photocells have shown the efficiency about 1.97% at fill factor about 61% and open-circuit potential about 0.56 V.