Nanoparticle size effect on optical and electrical properties of P3HT: ICxA photoactive layer

This study explores the relationship between P3HT: ICxA nanoparticle (NP) size and the performance of organic photovoltaic (OPV) devices. Four samples (S1-S4), prepared with different sodium dodecyl sulphate (SDS) concentrations, created varied NP sizes altered from 63.087 to 24.161 nm. Optical modeling technique predicted the highest current density of active layer can be generated by the NPs ink (S1, 63.087 nm average, 10.758 mA/cm²) compared to smaller NPs (S4, 24.161 nm average, 9.387 mA/cm²). Electrical measurements confirmed that the S1 exhibited the highest dark current (4.770 µA), conductivity (0.530 x 10⁻⁴ S/cm), and lowest resistivity (18.868 kΩ.cm), with a 44% improvement at illumination conditions. The current measurements at dark condition differed by ~50% between S1 and S4. Thermal treatments improved all samples by ~50% in comparison with RT conditions. This report findings revealed that the optimum performance of P3HT: ICxA NPs achieved when SDS concentration being in 20-30 mg SDS or at NPs size 63.087-38.434 nm NPs.