N‐type silicon solar cells with surface‐passivated screen‐printed aluminium‐alloyed rear emitter

Abstract

AbstractAluminium‐doped p‐type (Al‐p+) silicon emitters fabricated by means of a simple screen‐printing process are effectively passivated by plasma‐enhanced chemical‐vapour deposited amorphous silicon (a‐Si). We measure an emitter saturation current density of only 246 fA/cm2, which is the lowest value achieved so far for a simple screen‐printed Al‐p+ emitter on silicon. In order to demonstrate the applicability of this easy‐to‐fabricate p+ emitter to high‐efficiency silicon solar cells, we implement our passivated p+ emitter into an n+np+ solar cell structure. An independently confirmed conversion efficiency of 19.7% is achieved using n‐type phosphorus‐doped Czochralski‐grown silicon as bulk material, clearly demonstrating the high‐efficiency potential of the newly developed a‐Si passivated Al‐p+ emitter. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)