Development of Quantum Dot Sensitized Solar Cells with Reduced Fabrication Cost and Enhanced Conversion Efficiency

Abstract

Solar energy as a renewable energy source has become a public consensus as current fossil reserves are running out fast. Whilst in continuous pursuit of high efficiency solar cells, less efficient ones that can deliver significantly lower cost per kilowatt-hour should not be ignored. In this thesis, we outline the fabrication of low-cost quantum dot-sensitized solar cells (QDSCs) utilizing one-dimensional (1-D) electrospun nanostructures. From the very beginning of a minimum efficiency prototype fabricated by bi-functional molecular linker method, QDSCs with increasing efficiency were developed in phase through: 1) synthesis of novel rice grain-shaped TiO2 mesostructures by electrospinning; 2) efficient QDs deposition onto TiO2 by successive ionic layer adsorption and reaction (SILAR); 3) cobalt sulfide?s substitution of platinum as counter electrode to assemble all-SILAR based QDSCs. With further surface dipole treatment to engineer the band alignment between QDs and TiO2, QDSCs with greatly enhanced power conversion efficiency were successfully fabricated by single CdS sensitization without any elaborate procedures which provides a promising mass production and deployment way for alternative low-cost solar cells.