n-PERT solar cell achieves ‘record efficiency’

The n-PERT solar cell, fabricated on a large area wafer measuring 15.6 x 15.6cm, has been shown to achieve a top conversion efficiency of 21.5%. It features an open circuit voltage (Voc) of 677mV, a short circuit current of 39.1mA/cm² and 81.3% fill factor. It also includes a rear blanket p+ emitter obtained by boron diffusion. Jozef Szlufcik, director of imec's PV department, said: "Not withstanding the early development stage, the result shows very high efficiency potential of n-type PERT solar cells. "Moreover, n-type cells remain unaffected by light induced degradation present in p-type cells due to Boron-Oxygen complex, which results in improved long term energy yield and, therefore, lower total cost/kWh."