Evolution of high efficiency passivated emitter and rear contact (PERC) solar cells

In this chapter we discuss evaluation of PERC/PERT/PERL solar cells mainly from Al BSF solar cells. In the Introduction, the origin of PERC solar cells, current status, and future scope are discussed. Theory of photon absorption and optical generation is discussed in Section 4.2. Section 4.3 describes different electrical and optical losses usually taking place in solar cells. Carrier transport equations for flow of carriers in the solar cell and solar cell parameters are expressed in Section 4.4. The difference between industrial and laboratory PERC solar cell fabrication technology along with additional steps required with existing setup for Al BSF solar cells are discussed in Section 4.5. Different passivation layers and layer stacks required in fabrication of PERC solar cells are discussed in detail in this section. The performance of PERC solar cells for decades and also their improvements are discussed here. The detailed discussion of PERC technology, from starting wafer, followed by SDR, to firing of front and rear contacts is done in Section 4.6. Characterization units, which are required in PERC process flow, like scanning electron microscopy (SEM), doping profiler, thickness profiler, passivation thickness passivation quality, Suns-Voc, external quantum efficiency (EQE), I-V measuring systems, etc., are discussed in Section 4.7. We conclude in Section 4.8 and section "References" is provided after Section 4.8.