Contact passivation in silicon solar cells using atomic‐layer‐deposited aluminum oxide layers

Abstract

Abstract Atomic‐layer‐deposited aluminum oxide (AlO x ) layers are implemented between the phosphorous‐diffused n + ‐emitter and the Al contact of passivated emitter and rear silicon solar cells. The increase in open‐circuit voltage V oc of 12 mV for solar cells with the Al/AlO x /n + ‐Si tunnel contact compared to contacts without AlO x layer indicates contact passivation by the implemented AlO x . For the optimal AlO x layer thickness of 0.24 nm we achieve an independently confirmed energy conversion efficiency of 21.7% and a V oc of 673 mV. For AlO x thicknesses larger than 0.24 nm the tunnel probability decreases, resulting in a larger series resistance. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)