Space environmental testing of flexible coverglass alternatives based on siloxanes

• Published in: Polymer degradation and stability Vol. 98; no. 12; pp. 2503 - 2511
• Main Authors: Smeenk, N.J., Mooney, C., Feenstra, J., Mulder, P., Rohr, T., Semprimoschnig, C.O.A., Vlieg, E., Schermer, J.J.
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 01.12.2013; Elsevier
• Subjects: Applied sciences; Composites; cracking; Degradation; discoloration; Discolouration; Electron irradiation; electrons; Energy; Exact sciences and technology; Forms of application and semi-finished materials; irradiation; Natural energy; Panels; Photovoltaic cells; Photovoltaic conversion; Polymer industry, paints, wood; Polysiloxanes; Siloxanes; Solar cells; Solar cells. Photoelectrochemical cells; solar collectors; Solar energy; Space applications; Space environment; Technology of polymers; temperature; ultraviolet radiation; UV degradation; Siloxanes; Electron irradiation; Discolouration; UV degradation; Transparency; Coating material; Thermal ageing; Hybrid material; Electron beam; Experimental study; Silica; Composite material; Thermal stability; Solar cell; Thermal properties; Ultraviolet radiation; Optical properties; Photochemical stability; Artificial ageing; Radiochemical degradation; Transparent material; Siloxane polymer; Photochemical degradation
• ISSN: 0141-3910; 1873-2321
• DOI: 10.1016/j.polymdegradstab.2013.09.008

With the development of thin-film, high-efficient III–V solar cells using the epitaxial lift-off technique, flexible solar panels for space applications can be designed. Besides new deployment options, this also reduces the mass and thus launch costs of a satellite. One requirement for such a flexible panel configuration is the replacement of the brittle coverglass, which shields the solar cells from the harsh space environment, by a flexible alternative. In this work we have tested several compositions of a polysiloxane candidate material for a flexible shielding layer by exposing them to high energy UV and electron radiation at elevated temperatures. It was found that irradiation by electrons with a fluence corresponding to 15 years in space produces little degradation. UV radiation, on the other hand, has a more pronounced impact on the material properties, causing a discolouration of the transparent material and for some compositions even cracking of the samples.