Analysis and modeling of space radiation effects in quantum dot based nanomaterials for high-efficiency photovoltaic cells

For applications in satellite systems, devices based on novel nanomaterials offer significant advantages over traditional technologies in terms of light-weight and efficiency. Examples of such novel devices include quantum dot (QD) based solar cells and photodetectors. However, the response of these devices to radiation effects is not well understood, and radiation effects modeling tools are not yet available. In this paper we review our numerical models and experimental investigation of radiation effects in quantum dot based solar cells. In the natural, high-radiation environment of space all solar cells suffer from degradation. Although some studies have been conducted, and test data collected, on the performance of solar cells in a radiation environment, the mechanisms of radiation-induced degradation of quantum dot superlattices (QDS) has yet to be established. We have conducted proton irradiation experiments to provide a direct comparison of radiation hardness of quantum dot based cells and regular solar cells. An approach to the development of Nano-scale Technology Computer Aided Design (NanoTCAD) simulation software for simulation of radiation effects in QDS-based photovoltaic (PV) devices is presented. The NanoTCAD tools are based on classical drift-diffusion and quantum-mechanical models for the simulation of QD PV cells.