Approaching 22% efficiency with multicrystalline n-type silicon solar cells

The transition to seed assisted growth (high-performance multicrystalline silicon) significantly enhanced the quality of multicrystalline silicon. Combining the new growth technique with the inherent benefits of n-type doping results in a multicrystalline material which should be well suited for the fabrication of high-efficiency solar cells. In this work high-efficiency solar cells with passivating rear contact were fabricated on n-type highperformance multicrystalline silicon, crystallized at Fraunhofer ISE. The material features a high diffusion length >800 mm after application of all high temperature process steps needed for cell fabrication. Applying a black-silicon texture at the font resulted in a weighted reflectance of 1%, maintaining a good emitter passivation with J0 < 60 fA/cm2 for a 90 O/sq emitter. For the resulting n-type multicrystalline silicon solar cells conversion efficiencies up to 22.3% were reached, representing the current record for multicrystalline silicon solar cells.