Design of solar cell array preventing electrostatic discharge for satellite use

A new design of a cover glass which can be used for a solar cell array in a satellite is presented. The substrate of a cover glass used in this experiment is a ceria-doped microsheet glass. To minimize surface reflection and block ultra-violet, AR (anti-reflective) and UVR (ultra-violet reflective) coating are added to the substrate, respectively. The coating materials for AR and UVR are MgF/sub 2/ and Ta/sub 2/O/sub 5//SiO/sub 2/, respectively. ITO (indium tin oxide) coating also is added to substrate for preventing ESD (electrostatic discharge). The thickness of a ITO and coating sequence of AR, UVR, ITO are optimized, respectively. The computer simulation of the cover glasses with MACLEOD program showed that the transmittance of all cover glass were greater than 90%. In the optical test, the transmittance of AR/ITO/substrate and UVR/ITO/substrate are higher than that of ITO/AR/substrate and ITO/UVR/substrate. However, the threshold voltages for the onset of ESD of AR/ITO/substrate and UVR/ITO/substrate exceed 500 V. The cover glass shows a serious degradation when it is exposed to in UV radiation for 500 hours. However, the further degradation did not take place more after 500 hours exposition to UV radiation.