University of Delaware
The objective of this project is the engineering and optimization of perovskite photovoltaic (PV) cells for energy production in a number of areas, particularly extraterrestrial environments. Current PV technologies are unsatisfactory for use in missions outside of the inner solar system, which require highly efficient and cost-effective arrays. Accordingly, as the technology evolves new pathways emerge with the promise to satisfy these demands, such as PV cells containing mixed halide perovskite phase (CH3NH3PbI3-xClx). These perovskite PV cells exhibit high performance alongside economical synthesis techniques. Very recently these cells demonstrated conversion efficiencies exceeding 12%, with a Voc greater than 1 V. Of particular importance, and very impressively, these high quality devices can be prepared from simple and low cost, low energy solution-based spin coating techniques. The resulting absorber layer (<500 nm) requires annealing steps of no greater than 100°C, with complete device fabrication being carried out in ambient air. Overall, these lightweight, cost-effective, high performance materials align with the major criteria for the development the next generation of cells for interstellar travel. However, there are still a number of challenges associated with developing the perovskite PV cells, including noting performance limits, raw material consumption, and long-term stability, especially in space. This project is therefore initially directed at optimizing synthesis techniques, characterizing properties, and rating the performance of the perovskite PV cells. Variations in the structural, chemical, and optical properties of cells synthesized via spin coating or vacuum evaporation will be noted with techniques like electron microscopy, x-ray diffraction, and x-ray photoemission spectroscopy. PV performances will be quantified through voltage-current sweeps under simulated irradiation. The effects of composition, band-gap, morphology/structure, and chemistry on devices performance will be investigated. Over time this project will provide insight into the long-term stability of the materials and devices developed.