Photogeneration process in bulk heterojunction solar cell based on quaterthiophene and CdS nanoparticles

In this paper, the blended systems composed of organic oligothiophenes and CdS nanoparticles were investigated through their optical and photoelectrical measurements for their potential applications in photovoltaic devices. The electrical and photoelectrical properties of the devices fabricated with the active layer sandwiched between the metal anode and the metal cathode have been reported. Dependence of the performance of this bulk heterojunction photovoltaic device on their composition has been investigated with respect to charge transport. The organic/inorganic interface area in bulk heterojunction is an important factor in the photovoltaic process. The incorporation of nanoparticles in the polymer matrix, for the purpose to fabricate hybrid inorganic-organic materials, could be a good alternative to enhance the charge generation process of free carriers. The J-V curves of the quaterthiophene (4T) and hybrid quaterthiophene/cadmium sulfide nanoparticles CdS show the important role played by the nanoparticles for energy conversion improvement. The experimental data were found to be in good agreement with a modified Braun-Onsager model.