Fabrication, characterization and modeling of thin silicon tandem cell on foil in four terminal configuration

The investigation samples of amorphous/microcrystalline silicon and silicon-germanium cells were made at low and high pressure as well as in graded H₂, SiH₄, GeH₄ flows and various plasma power conditions by RF PECVD on a glass and also on a foil and were analyzed in four terminal configuration. The authors focused on fabrication of protocrystalline and microcrystalline Si and SiGe solar cells with 6%-8% efficiency, and on projecting of thicknesses of component cells as well as designing of a role of the back reflector to obtain the current and absorbed light matching in the configuration. The analyses of light transmissions and reflections, I-V-C light and dark characteristics as well as two light beam quantum efficiency measurements for the components were conducted.