V-Groove Multijunction (VGMJ) Solar Cells
The V-groove multijunction (VGMJ) solar cell consists of an array of many individual diode elements connected in series to generate a high-voltage low-current output This represents a fundamental difference between a conventional singlejunction solar cell, in which the output voltage is less than one volt. All cell elements are formed simultaneously from a single silicon wafer using a V-groove etching process. Computer simulation predicts a conversion efficiency better than 28 percent for this device when operated in sunlight concentrated 100 times or
more (suns > 100). The major advantage of this solar cell over other conventional silicon cells include a conversion efficiency in excess of 25 percent after considering various losses, assuming modest bulk carrier lifetimes, a higher open-circuit voltage, a very low series resistance, a simple fabrication process involving one mask, and reliable and robust environmental protection provided by a glass front surface with improved mechanical integrity.