Comparative Charge Transport Study of MEHPPV-TiO₂ and P3HT-TiO₂ Nanocomposites for Hybrid Bulk Heterojunction Solar Cells.

TiO₂ nanorods integrated with poly[2-methoxy,5-(2-ethylhexyloxy)-p-phenylenevinylene] (MEHPPV) and poly(3-hexylthiophene) (P3HT) matrixes were investigated for charge transport properties to evaluate their potential application in a hybrid solar cell device. An exhaustive characterization was performed to identify the best hybrid nanocomposite among MEHPPV-TiO₂ and P3HT-TiO₂. The analysis involved optical and electrical characterization techniques such as the X-ray diffraction, field emission scanning electron microscope, energy dispersive X-ray spectroscopy, Fourier transform infrared spectroscopy, ultraviolet-visible spectroscopy, photoluminescence, atomic force microscopy, X-ray photoelectron spectroscopy, and I-V measurements. TiO₂ nanorods exhibited excellent dispersion in both polymer matrixes, thus significantly improving the photocurrent generation and net efficiency. Therefore, the overall device performance was improved. The findings of this study demonstrated that the P3HT-TiO₂ photovoltaic device exhibited superior performance than the MEHPPV-TiO₂ photovoltaic device. We believe that this evaluation would certainly contribute to the understanding of interfacial exciton dissociation in nanoscale morphology for the next-generation hybrid bulk heterojunction solar cells.