STRUCTURAL ANALYSIS OF GAAS-BASED PV CELLS AFTER IONIZING IRRADIATION

Morphology and structural analysis of photovoltaic cells based on GaAs before and after high dose gamma radiation of 500 kGy was investigated. Cobalt-60 emitter was used as the synthetic radioactive isotope. This radioactive form of cobalt is commonly used for space instruments and devices testing. Atomic force microscopy (AFM) was used to study the morphology and roughness differences. Cross-sectional investigation using transmission detector to thin layers observing was performed. Also, with use of sputtering system of Secondary Ion Mass Spectroscopy (SIMS) a detailed molecular and elemental information about the surface top layers was showed. Another molecular and structural changes in the top layers using two optical methods of Raman spectroscopy and spectrophotometry were also identified.