The optimization of organic photovoltaic (OPV) devices based on a thin-film blend of the polymer poly(3-hexyl thiophene) [P3HT] and the fullerene [C60] was explored. To achieve an efficient photo induced charge transfer, the following aspects have been studied: (1) Determination of the donor/acceptor composition ratio that yields good film interface and high photon absorption; (2) Selection of suitable Nanoparticle to obtain optimal absorption spectrum and good efficiency; (3) Thermal annealing process to enhance the photon absorption, improve the short circuit current and the filling factor, and therefore the efficiency of the devices. In particular, the preparation of the composition and thermal treatment of the active layer along with the effect of Nanoparticle's presence are addressed. In addition, the use of Nanoparticle (WO3) into the P3HT/C60 layer to improve the power conversion efficiency (PCE) of the device is investigated. WO3 Nanoparticle's doped poly(3-hexylthiophene) and C60 blends (P3HT:C60: WO3) have been produced as the photoactive layer of organic photovoltaic devices (OPVs). The 40 ppm WO3 doping OPVs exhibit higher power conversion efficiency (PCE) than other OPVs.

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