Cold plasma-deposited SiO2 and amorphous Teflon AF as electret-coatings for MIS-IL solar cells

Novel thin film materials, namely cold plasma-deposited SiO₂ and spin-coated Teflon AF have recently been identified as useful electrets; the present paper briefly summarises preparation conditions and material characteristics, the main attention being focused on the applicability of these electrets to MIS-solar cells (Metal Insulator Semiconductor). As a functional coating, the electret passivates the surface and generates a permanent electric field which induces an inversion zone at the silicon surface between the metal lines of the front electrode. It is shown that the I-V-characteristic drastically depends on the polarity and density of the electret space charge. Hence, electrets in solar cell technology can be an important means to increase the device efficiency, and to study silicon-insulator interfaces