Mesoporous ZnO/TiO2 nanowire heterojunction photo-anodes for quantum-dot sensitised solar cells

Abstract

Research into quantum dot-sensitised solar cells (QDSSCs) is crucial for advancing sustainable energy solutions due to their unique advantages over conventional solar technologies. QDSSCs offer the potential for high power conversion efficiencies by leveraging the tunable bandgaps of quantum dots (QDs), which allow for broad spectral absorption and efficient light harvesting across the solar spectrum. Their low-cost fabrication such as solution processing and printing techniques, make them economically attractive for large-scale production and flexible applications. QDSSCs can also operate effectively under low-light conditions and offer design versatility, opening pathways for integration into diverse environments and products. This ongoing research is vital for developing next-generation solar cells that are not only more efficient and affordable but also more adaptable to various energy demands, contributing significantly to global efforts in renewable energy. Zinc oxide nanowires (ZnO2 NWs) offer an interesting alternative to traditional titanium dioxide (TiO2) as an electron transport layer in QDSSCs primarily due to their superior electron mobility and direct growth capabilities. Their one-dimensional nanostructure provides a direct pathway for electron transport, significantly reducing recombination losses and enhancing charge collection efficiency. ZnO NWs may be grown at lower temperatures and offer greater flexibility in morphology control, allowing for tailored architectures that optimise light harvesting and QD dot loading. This combination of excellent charge transport properties, tunable morphology and cost-effective synthesis makes ZnO NWs a highly promising material for developing more efficient and scalable QDSSCs.