Advances in a baseline process towards high efficiency c-Si solar cell fabrication

This paper shows a baseline process to fabricate high efficiency solar cells that are based on the Passivated Emitter and Rear Cell solar cell concept. The idea is to define a very flexible process in order to see, for comparison, the benefits of introducing alternative fabrication steps. For instance, new structures based on laser firing contacts and rear passivation with deposited PECVD a-SiCx: H layers are planned to be fabricated following the baseline process outlined hereby. In its design, special attention is paid to the front metallization grid and rear point contact design. Preliminary results using Cz p-type 2.8 Omegaldrcm substrates yields photovoltaic efficiencies up to 18.6% in a 1 cm² cell with open circuit voltage of 628 mV and an outstanding photocurrent density of 39 mA/cm². Efficiencies of about 21.5% are predicted for the improved devices.