Influência de nanopartículas de ferritas na fotoluminescência de filmes finos de P3HT:PCBM

Abstract

Recent studies have unequivocally demonstrated that the addition of small amounts of magnetic nanoparticles to the active layer of P3HT:PCBM-based cells contributes to increasing conversion efficiency. This work investigated the influence of ferrite nanoparticles on the photoluminescence of BHJ thin films of P3HT:PCBM in order to help elucidate this issue. Films were deposited by the spin-coating technique and characterized by uv-vis and photoluminescence spectroscopy techniques. Ferrite nanoparticles MFe 2 O 4 (M = Co, Ni and Zn) in different concentrations (1%, 4% and 7%) were added to some films and the results were compared with those obtained from films without doping. The nanoparticles were synthesized by the low-cost method called protein sol-gel. The addition of ferrite nanoparticles to BHJ films caused a suppression of photoluminescence when compared to films without doping. This suggests an increase in the dissociation efficiency of excitons, which leads to a higher density of free charges and therefore justifies the increase in the conversion efficiency of organic solar cells reinforced with these nanoparticles. It was determined that the most effective doping was 4% for the three ferrites, as it showed greater suppression of the emission spectrum. Cobalt ferrites was one that showed the greatest suppression for all doping levels. The results indicate that the doping of the active layer of solar cells based on BHJ filmes of P3HT:PCBM with 4% CoFe 2 O 4 may lead to a better performance in the energy conversion of the solar device.