In the present work, chemical-free aluminium nanoparticles (Al NPs) have been incorporated inside active layer of organic solar cell (OSC) using a new ultrasonic ablation technique, by which the Al NPs have been physically prepared in 1,2-dichlorobenzene (DCB) as a solvent for preparing solar cell active layer. The concentration of Al NPs inside active layer can be increased by increasing the volume of DCB-Al NPs and, also, by increasing the ultrasonication time applied upon DCB-Al NPs mixture. The prepared Al NPs are incorporated inside the common P3HT:PCBM active layer without accumulation and with low distribution. Optical absorption of the P3HT:PCBM active layer is improved through plasmon resonance induced by Al NPs inside active layer. The fill factor (FF) is, also, improved by the presence of Al NPs which facilitate charge carrier transfer in the P3HT:PCBM solar cell. The FF can be reduced due to presence of Al bulk pieces inside active layer. However, these Al bulk pieces are dissociated under the effect of ultrasonic irradiation for longer time. Optical absorption as well as charge carrier transfer induced by Al NPs are the responsible to increase performance parameters of the P3HT:PCBM solar cell under increasing the concentration of Al NPs inside OSC. As a conclusion, the incorporation of Al NPs inside P3HT:PCBM solar cell induces a significant improvement of the FF by 35% and consequently, the PCE is improved with about 39%.
Extracting Information about the Electronic Quality of Organic Solar-Cell Absorbers from Fill Factor and Thickness
