Oomman Varghese1
University of Houston1
The advent of zero dimensional (0D) nanomaterials such as quantum dots (QD) of semiconductors has brought renewed expectations in direct solar energy conversion technologies such as solar photovoltaics and photoelectrochemical (PEC) fuel generation. The few-atom construction of the QDs furnishes them with very large surface area relative to volume leading to unique characteristics. The phenomena such as quantum confinement effects and associated blue shift in the absorption edge are not only scientifically intriguing but also capable of bringing paradigm shifts in the solar power as well as fuel generation technologies. The efficiency of the single junction devices from these technologies can reach levels significantly beyond the Shockley-Queisser limit utilizing phenomena such as multiple exciton generation and hot carrier extraction. While this milestone has not yet been achieved, there has been substantial improvements in the efficiency of the QD based solar cells. These solar cells have utilized materials from chalcopyrites to inorganic iodide perovskites as light absorbers and the efficiency has reached 18%. Carbon dots and band gap engineered QDs of wide band gap materials such as boron nitride appeared promising for solar PEC water splitting and carbon dioxide reduction. It has also been demonstrated that the potentials of the quantum dots can be extended further if they are supported by high surface area ordered nanostructures. This presentation will review the advances in supported QD based solar cells and solar fuel generation processes.