Complex sentence: However, as all of these technologies normally use high-temperature deposition techniques, traditionally the best performance comes from cells deposited on glass, and even then the performance is marginal compared to modern polysilicon-based panels.
Split into simpler sentences: However, as all of these technologies normally use high-temperature deposition techniques, the best performance normally comes from cells deposited on glass. Even then the performance is marginal compared to modern polysilicon-based panels.