Enhanced Photovoltaic Performance of Hybrid Solar Cells with a Calcium Interfacial Metal Electrode

A better understanding of how the interfacial layer influences charge carrier recombination would benefit the development of high-efficiency hybrid solar cells (HSCs). HSCs based on poly(3-hexylthiophene) (P3HT)/Si nanoparticles (Si NPs) with three identical electrodes were used as reference system to investigate the interfacial layer effects on device performance. The standard solar-grade silicon was produced using rice husk ash (RHA) as a biogenic source. The RHA was purified by using a low-cost and simple method followed by modified magnesiothermic reduction reaction to produce crystalline Si NPs. Prepared Si NPs as an acceptor material with different percentages of Ca interface layer metal electrodes on HSCs were studied. A highly conductive electrode was one of the important factors for enhancing the fill factor and power conversion efficiency (PCE). For fabrication and characterization of P3HT/Si NP HSCs with three identical thermally evaporated electrodes, Al (100 nm), Ca/Al (10 nm/90 nm), and Ca/Al (20 nm/80 nm) were used as top electrode. The device with a Ca/Al (10 nm/90 nm) electrode exhibited a lower recombination, while its efficiency was 20% and 10% higher than the devices with the Al (100 nm) and Ca/Al (20 nm/80 nm) electrodes, respectively.