Self-Defending Pseudomorphic Glass Against Atomic Oxygen for LEO Flexible Photovoltaic Encapsulation

The degradation of polymer materials in the atomic oxygen (AO) environment of low Earth orbit (LEO) significantly limits their application in lightweight spacecraft power systems. In this work, we investigate self-defending pseudomorphic glass (PMG) designed for flexible photovoltaic encapsulation. PMG exhibits an erosion rate only 13% of that of Kapton® after 2 × 10²¹ atoms /cm² of AO exposure. PMG encapsulation effectively maintained the critical photovoltaic cell parameters, with negligible degradation in open-circuit voltage (Voc, 0.10%) and short-circuit current (Isc, 0.21%), as well as a stable external quantum efficiency over the entire measured spectral range. During AO exposure, PMG forms a protective SiO_X layer that functions as a self-defending barrier through continuous oxidative cross-linking, thereby minimizing optical degradation and preserving the power-generation performance of encapsulated solar cells. The inclusion of glass beads further enhances AO resistance by acting both as a reinforcing phase and as sites for energy dissipation. This study provides a viable strategy for fabricating high-performance, AO-resistant polymer composites for space photovoltaic encapsulation applications.