Characterization of Biologically Derived Substrates for Thin-film Crystalline Silicon Solar Cells

The novel low-cost biologically derived substrates made of biogenic materials such as high-density fiberboards, felt and paper based compositions are investigated by using microscopy techniques. Plates from these materials were carbonized or graphitized, pressed and diced. In order to seal the surface of the substrates they were processed through different post treatments such as siliconization by capillary effect or pack cementation, alternatively they were covered by a silicon carbide (SiC) layer by chemical vapor deposition (CVD). The substrates were studied regarding their surface properties by using conventional and confocal white-light microscopy. The study revealed different roughness characteristics as well as micro cracks in some of the substrates. Different crystalline silicon thin-film layers deposited on these substrates for solar cell fabrication were investigated by employing scanning electron microscopy (SEM) of layer crosssections.