Influence of texture feature size on spherical silicon solar cells

The effects of surface texturing on spherical silicon solar cells were investigated. Surface texturing for spherical Si solar cells was prepared by immersing p-type spherical Si crystals in KOH solution with stirring. Two kinds of texture feature sizes (1 and 5 mu m pyramids) were prepared by changing stirring speed. After fabrication through our baseline processes, these cells were evaluated by solar cell performance and external quantum efficiency. The cell with 1 and 5 mu m pyramids shows the short circuit current density (J(sc)) value of 31.9 and 33.2 mA center dot cm(-2), which is 9% and 13% relative increase compared to the cell without texturing. Furthermore, the cell with 5 mu m pyramids has a higher open-circuit voltage (0.589 V) than the cell with 1 mu m pyramids (0.577 V). As a result, the conversion efficiency was improved from 11.4% for the cell without texturing to 12.1% for the cell with 5 mu m pyramids.