A Review of Various Nanostructures to Enhance the Efficiency of Solar-Photon-Conversions

Abstract

The problem of dwindling energy can be attributed to the rapidly increasing worldwide energy demand, leading to an urgent need for alternative energy-harvesting technologies to sustain the economic growth by maintaining our appetite for energy. Among them, solar-energy-harvesting is most promising, and the huge demand for clean, cost-effective, and cost-efficient energy can be met by solar energy. The large-scale solar energy utilization has not become practical because of the high cost and inadequate efficiencies of the current solar-energy-conversions. Nanotechnology offers tools to develop cost-effective and cost-efficient technologies for solar-energy conversions. Nanostructures, such as nanowires, nanopillars, nanodomes, nanorods, quatumdots, nanoparticles, etc., facilitate photon absorption, electron transport, and electron collection properties of the solar-energy-conversion devices. This review specifically summarizes the contribution of the nanotechnology to photovoltaics, dye-sensitive solar cells, quantum-dot-sensitized solar cells, and solar hydrogen production devices.