Grant: Engage Grants Program

High demand for clean electricity has led in the past years to a great diversity of solar energy conversion concepts and attempts to improve the efficiency of existing solar cells. The basic structure of a solar cell consists of conventional crystalline semiconductor bipolar junctions. Using different materials to absorb different spectral portions of sunlight is a well known practice for improving the efficiency of solar cells. Conventionally, this can be achieved by using mechanically stacked or monolithic tandem structures. More advanced solar cells are based on nano-structures (quantum wells and/or quantum dots) and were originally proposed as an alternative to multi-junction devices. Those nano-structures are fabricated from very thin (of the order of 100 Angstroms, or 1/100000000 meters) layers of various semiconductor materials. The objectives of this proposal are to develop mathematical models and the relevant software simulation tools to describe dynamical physical processes in the operation of solar cells based on quantum dots. Those important processes are known as carrier capture and escape. We will analyze the role of those processes on the photocurrent of solar cells. The outcomes of our research will be an understanding of the optimal band energies of quantum dots for achieving the maximum photocurrent, and possible limitations due to those processes on the efficiencies of solar cells. The research results will be in the form of physical models and, based on them, written software. In due process, the software will be used to simulate new and improved designs of solar cells with increased efficiencies. This research is important to Cyrium Technologies (the supporting Company), which produces solar cells based on novel technology utilizing quantum dots, to optimize and to improve cell performance for terrestrial generation of power. This technology is poised to revolutionize the generation of solar energy. The current efficiencies of Cyrium cells are about 40% and are among world leaders; there is still room for improvement and the research proposed here is one step in that direction.