Bulk heterojunction solar cells based on polyaniline/multi wall carbon nanotube: from morphology control to cell efficiency

In this study, polyaniline/multiwall carbon nanotube nanocomposite (PANI/MWCNT) was first synthesized, and a simple organic solar cell was then fabricated containing PANI/MWCNT with cauliflower morphology as an active layer. In the next step; the influence of different parameters such as MWCNT content, the cathode buffer layer, the electrolyte and the presence of dye on the efficiency were experimentally investigated. The effect of carbon nanotubes weight percent on efficiency was studied by measuring the band gap using the UV-Vis characterization. In order to detect the chemical bonding between MWCNT and PANI, the Fourier transform-infrared spectroscopy was used. Also in order to investigate morphology, field emission scanning electron microscopy images of the composite were obtained, and conductivity properties were measured using a standard 4-point DC/voltage method at room temperature. The results showed that by increasing the amount of MWCNT in the composite, the band gap decreased and thus the cell efficiency increased. In a multi-layer cell with cauliflower morphology, due to the excellent synergy between the active layer of PANI/MWCNT and the dye cell components, a significant increase in photovoltaic profile was observed in comparison with simple cells with cauliflower morphology.