Effect of UV-activated TiO<sub>2</sub> Nanoparticles on the Properties and Performance of PAni-TiO<sub>2</sub> Nanocomposite Films for Solar Cell Applications
F.M. El-Hossary, Ahmed Ghitas, A. M. Abd El-Rahman, A. A. Ebnalwaled, M. Abdelhamid Shahat, Mohammed H. Fawey
Abstract
Abstract To improve the performance of organic solar cells by enhancing the properties of the photoactivated nanocomposite layer, the UV irradiation process was used to activate titanium dioxide nanoparticles (TiO 2 NPs). Herein, polymer solar cells were fabricated with FTO/(PAni-TiO 2 )/Ag system. A series of mixed polyaniline (PAni) with 20% of activated TiO 2 NPs at different processing times was used to form PAni-TiO 2 nanocomposite films. The structural evolution, surface characteristics, optical and electrical properties of PAni-TiO 2 films have been investigated. XRD patterns showed that the UV treatment of TiO 2 NPs increased the crystallite from 18.35 to 24.1 nm and the degree of crystallinity increased by 5.6%. The irradiated PAni-TiO 2 films showed a rougher and more porous surface compared to the untreated one. Moreover, the adhesion force and electrical conductivity of the treated nanocomposite films at 8 h improved to be 137 mN/m and 6.62 S/m, respectively. Incorporation of activated TiO 2 NPs exposure to UV for different times from 0 to 8 h with the PAni matrix enhanced the current density (J sc ) of PAni-TiO 2 based nanocomposite solar cells from 3.11 to 4.83 (mA/cm 2 ) and their efficiency from 0.33 to 0.85%. The increase in the solar cell efficiency is mostly ascribed to a structural change accompanied by a rapid increase in surface roughness, which led to a decrease in the reflected photons and thus an increase in the charge carriers produced. These results revealed the effect of surface UV irradiation of TiO 2 NPs on their structural properties and the electronic contact between PAni and TiO 2 NPs, which greatly influenced the amount of carrier transport within the PAni-TiO 2 composites.