Rear Side Diffractive Gratings for Silicon Wafer Solar Cells

Abstract

This chapter discusses how rear side diffractive gratings can be applied for light trapping in solar cells. Light diffracted into higher orders travels along an oblique path and is totally internally reflected. The change of direction and the internal reflection provide the desired enhancement of the optical path length and absorption. One reason for gratings having experienced a very high level of attention is that gratings have a very high potential for light trapping. Optimizing gratings is a complex task and needs to be done on a case to case basis. This task requires sophisticated simulation and investigation methods that are explained in this chapter. The realization of gratings in solar cells requires high-precision texturing techniques in the micrometer and sub-micrometer range. A short overview of the most important characterization techniques for solar cells with diffractive grating is given.