Perovskites and Other Emerging Photovoltaic Technologies for Space Applications

Perovskite solar cells have emerged as promising candidates for space applications owing to their high absorption coefficient, which allows for sub-micron cell thicknesses, and to their promising radiation tolerance. They have been fabricated on thin (<2 μm) flexible polymer superstrates, allowing for specific power up to ~30 kW/kg at the cell level, dramatically higher than other cell technologies. However, the space environment subjects solar cells to ionizing radiation and elevated operating temperatures, which for conventional space photovoltaics, requires the addition of radiation shielding coverglass for radiative cooling and to prevent premature degradation of the efficiency. Conventional coverglass typically ranges from 70—200 μm in thickness, and would substantially erode the specific power advantage of ultrathin perovskites. It is thus of interest to study the stability of perovskite solar cells in the space environment, to determine how much shielding or cooling materials would be necessary for use in various orbits or mission lifetimes. We will present the results of prior and ongoing radiation studies including high-energy electrons and low-energy protons, and discuss the viability of thin polymer substrates and shielding materials. Our research also includes other emerging photovoltaic technologies for space applications, including luminescent solar concentrators, nanostructured III-Vs for improved radiation hardness, and low-cost diffused-junction GaAs cells. We will discuss developments in these cell technologies and our present effort to measure the behavior of research devices in low-earth orbit.