Bifacial microcrystalline silicon solar cells with improved performance due to μc-SiOx:H doped layers

Abstract

We present the development and application of n-type hydrogenated microcrystalline silicon oxide (μc-SiOx:H) in semitransparent bifacial microcrystalline silicon (μc-Si:H) solar cells. Semitransparent bifacial solar cells are of interest for a number of technical applications like building integration or concentrator devices, but also can offer new insight into solar cell properties due to the possibility to illuminate the cell from both sides. Appropriately selected μc-SiOx:H n-layers with low refractive index and high optical band gap allow the reduction of the reflection of the cells and improve short circuit current density (JSC) and conversion efficiencies. The quality of n-type μc-SiOx:H window layers is demonstrated in solar cells with highly reflective ZnO/Ag contacts. High JSC values of 24.8 mA/cm2 and efficiencies of 9.5% are obtained for 1 μm thick solar cells.