24% efficient PERL structure silicon solar cells

The performance of silicon solar cells has been significantly improved using an improved PERL (passivated emitter, rear locally diffused) cell structure. This structure overcomes deficiencies in an earlier PERC (passivated emitter and rear cell) cell structure by locally diffusing boron into contact areas at the rear of the cells. Terrestrial energy conversion efficiencies of up to 24% are reported for silicon cells for the first time. Air Mass 0 efficiencies approach 21%. The first batches of concentrator cells using this structure have demonstrated significant improvement, with 29% efficient concentrator silicon cells expected in the near future.<>