Effectively surface-passivated aluminium-doped p+ emitters for n-type silicon solar cells

✍ Scribed by Rauer, Michael ;Schmiga, Christian ;Hermle, Martin ;Glunz, Stefan W.

• Publisher: John Wiley and Sons
• Year: 2009
• Tongue: English
• Weight: 215 KB
• Volume: 207
• Category: Article
• ISSN: 0031-8965
• DOI: 10.1002/pssa.200925507

✦ Synopsis

Abstract

We present a detailed study on surface‐passivated screen‐printed aluminium‐alloyed emitters for back junction n‐type silicon solar cells. We investigated (i) two different commercially available aluminium pastes and (ii) two passivation layers both well suited for highly doped p^+^ silicon: plasma‐enhanced‐chemical‐vapour‐deposited amorphous silicon (a‐Si) and atomic‐layer‐deposited aluminium oxide (Al~2~O~3~). We show that for the formation of a homogeneous, non‐shunted emitter, a careful choice of the alloying conditions is essential. Moreover, for a most effective surface passivation, low emitter thicknesses have to be used. Combining these two aspects, we have achieved extraordinary high implied open‐circuit voltages of 673 mV for a‐Si‐ and 685 mV for Al~2~O~3~‐passivated Al‐alloyed emitters, corresponding to emitter saturation current densities of 128 and 55 fA/cm^2^, respectively.