Creating resilient photovoltaics for space exploration

With the market for near-Earth satellites growing, so does the need for long-term, reliable solar power. The expected growth of orbital satellites demands photovoltaics (PVs) with a larger energy capacity and reliability than the multijunction III-V PVs now in use.

No matter the makeup, however, PV modules are susceptible to charged particle radiation, which can lead to degradation. Zawisza et al. investigated the effects of this radiation on cadmium telluride-based (CdTe) PVs.

“The potential value of CdTe single-junction solar cells and their use as a partner in a tandem solar cell have been underappreciated,” said author Scott Lambright.

They tested copper- and arsenic-doped cadmium selenide telluride (CdSeTe) PVs and found they were resilient against proton radiation and led to a better efficiency remaining factor — the fraction of performance that remains when comparing pre-exposure devices to post-exposure devices — relative to multijunction III-V PVs.

Copper-doped PVs outperformed two of the three multijunction III-V PVs used for comparison in this study in photoconversion efficiency after a three-year simulation in a medium-Earth orbit radiation environment.

“Considering that satellites are generally designed around the end-of-life performance of their power systems, this suggests that CdSeTe-based PV modules are the preferable technology for high-exposure or long service-life missions,” Lambright said.

The researchers plan to continue testing CdSeTe PV cells based on current standards for space PV cells and continue investigating the nature of the degradation caused by charged particle radiation.

“These studies will investigate specific defects, including their energies, densities, and stability — in an effort to understand the primary causes of reductions in efficiency and how the various defects may heal under thermal and/or light-based annealing conditions,” Lambright said.

Source: “Proton radiation resilience of CdSeTe photovoltaics: High predicted end-of-life performance for space applications,” by Zachary W. Zawisza, Scott Lambright, Aesha P. Patel, Sabin Neupane, Tamara Isaacs-Smith, Patrick Chen, Molly Smith, Robert Snuggs, Samuel S. Erickson, James Becker, Ebin Bastola, Abasi Abudulimu, Richard Irving, Adam B. Phillips, Michael J. Heben, Yanfa Yan, Zhaoning Song, and Randy J. Ellingson, APL Energy (2025). The article can be accessed at https://doi.org/10.1063/5.0282712 .

This paper is part of the Energy Materials for Extreme Environments Collection, learn more here .