Quantum dot photovoltaics have the potential to exceed theoretical efficiency limits of other photovoltaic devices and represent a potentially disruptive next-generation technology. In this thesis I present my efforts to develop and characterize novel quantum dot materials that have superior multi-exitonic, optical, and electronic properties. Several methods for the synthesis of inverse type-II core shell quantum dots are explored and their associated challenges are presented. A variety of materials characterization techniques are implemented to investigate these materials. Lastly, a collaborative investigation of the electronic properties of high performance lead sulfide quantum dots is presented.

Models of solar fuels devices that are completely electrochemically-mediated and consist of ensembles of optically thin light absorbers were used to calculate their maximum theoretical solar-to-fuel efficiencies. These models are based on the thermodynamic principles of detailed balance and blackbody radiation, semiconductor device physics, and simple catalysis. The maximum efficiency of an electrochemically-mediated tandem water splitting device was calculated and the crucial dependence of this efficiency on the redox shuttle thermodynamic potential was elucidated. A novel model of a stack of optically thin, radiatively coupled light-absorbers that each independently perform solar fuels reactions was developed to demonstrate the substantial gains in solar-to-fuel efficiency that are possible when using ensembles of small light-absorbers. The results presented herein can be used by researchers to develop high-efficiency, low-cost solar fuels materials and devices.