High efficiency n -type Si solar cells on Al 2 O 3 -passivated boron emitters

• Published in: Applied physics letters 2008-06, Vol.92 (25), p.253504-253504-3
• Main Authors: Benick, Jan, Hoex, Bram, van de Sanden, M. C. M., Kessels, W. M. M., Schultz, Oliver, Glunz, Stefan W.
• Format: Article
• ISSN: 0003-6951; 1077-3118
• DOI: 10.1063/1.2945287

In order to utilize the full potential of solar cells fabricated on n -type silicon, it is necessary to achieve an excellent passivation on B-doped emitters. Experimental studies on test structures and theoretical considerations have shown that a negatively charged dielectric layer would be ideally suited for this purpose. Thus, in this work the negative-charge dielectric Al 2 O 3 was applied as surface passivation layer on high-efficiency n -type silicon solar cells. With this front surface passivation layer, a confirmed conversion efficiency of 23.2% was achieved. For the open-circuit voltage V oc of 703.6 mV , the upper limit for the emitter saturation current density J 0 e , including the metalized area, has been evaluated to be 29 fA ∕ cm 2 . This clearly shows that an excellent passivation of highly doped p -type c - Si can be obtained at the device level by applying Al 2 O 3 .