Thin and low light-induced degradation passivated emitter and rear cells based on boron-aluminum pre-gettering

Abstract

In the present work, B/Al pre-gettering technique was proposed to suppress the light-induced degradation (LID) of thin (150 μm) monocrystalline passivated emitter and rear cell (PERC). B/Al co-doping technique raised the acceptor concentration in p + doping area by more than one magnitude, contributing to the superior gettering effect with the interstitial iron concentration decreased from 9.58e10 cm−3 to a minimal value of 4.93e9 cm−3. By employing pre-gettering process in the thin PERC solar cells fabrication, LID was suppressed dramatically, with the efficiency loss improvement of 0.63% and 0.44% for the maximum degradation and ultimate degradation, respectively. Accordingly, although B/Al pre-gettering degraded the electrical performance slightly, the ultimate efficiency after LID was 0.06% higher than the samples without pre-gettering, reaching 20.68%. The present work will be helpful to deepen the understanding of B/Al gettering effect as well as suppress LID induced by iron atoms.