The NOA | Salomé Group continues to strengthen its commitment to space technologies, with a new publication addressing a critical challenge for the deployment of photovoltaic technologies beyond Earth: understanding how solar cells respond to the harsh radiation environment encountered in space.
Published in physica status solidi (RRL) – Rapid Research Letters, the study “Performing Relevant Irradiation Experiments: The Role of Proton Flux in the Dynamic Annealing during Irradiation of Cu(In,Ga)Se₂-Based Solar Cells” investigates how proton irradiation flux influences the radiation hardness of CIGS thin-film solar cells. The work brings together INL, the University of Aveiro and Instituto Superior Técnico, INESC-MN.
Making irradiation experiments more representative of space
Solar cells designed for space applications must withstand prolonged exposure to energetic particles. Laboratory irradiation experiments are therefore essential for assessing their suitability, but reproducing the relevant conditions requires careful consideration of several irradiation parameters.
In this work, two CIGS solar cells were exposed to 1 MeV protons at approximately the same total fluence (~10¹³ H⁺ cm⁻²), but using different proton fluxes. The results demonstrate that flux itself has an important influence on both the magnitude and nature of the resulting radiation damage.
The study links these differences to the competition between radiation-induced defect generation and dynamic annealing. While proton irradiation generates defects in the CIGS absorber, the energy transferred during irradiation can also promote local heating and partial defect recovery. Increasing the proton flux may therefore enhance these dynamic annealing processes.
Building knowledge for photovoltaics in space
These findings have an important implication: proton flux should be considered alongside energy and fluence when designing radiation-hardness experiments for space photovoltaic technologies. Accurately defining these parameters is essential to ensure that laboratory tests provide meaningful information about how photovoltaic devices will perform in actual space environments.
The publication contributes to NOA’s broader activities in CIGS photovoltaics, advanced materials, device physics and solar cells for demanding environments. Lightweight, flexible and radiation-resistant thin-film photovoltaics are particularly attractive for space applications, where specific power, reliability and reduced mass are critical.
By combining our long-standing expertise in CIGS solar cells with advanced nanotechnology, characterization and device engineering, we aim to further expand the role of the NOA | Salomé Group and INL in space technologies, translating fundamental understanding of materials and devices into technologies capable of operating under the challenging conditions of future space missions.
https://onlinelibrary.wiley.com/doi/full/10.1002/pssr.202500374