Influence of Base Resistivity on Solar Cell Parameters of Double-Side Contacted Rear Junction Solar Cells

• Published in: Energy procedia Vol. 27; pp. 53 - 58
• Main Authors: Mertens, V., Ballmann, T., Lee, J.Y., Junghänel, M., Stenzel, F., Brandt, L., Schulze, A., Engelhart, P., Müller, J.W., Wawer, P., Küsters, K.H.
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 2012
• Subjects: base resistivit; n-type silicon; rear junction solar cell; rear junction solar cell; base resistivit; n-type silicon
• ISSN: 1876-6102; 1876-6102
• DOI: 10.1016/j.egypro.2012.07.028

We study the dependence of solar cell parameters on base resistivity for double-side contacted n-type rear junction solar cells with boron emitter and local rear contacts. Experimental data for solar cells processed on n-type Cz Si wafers with base resistivities ranging from 2Ω·cm to 16Ω cm are compared to device simulations for the respective resistivity range. Our experimental data show the typical strong increase of efficiency with base resistivity in the range of 2 - 5Ω cm and at about 10Ω cm a saturation of efficiency with base resistivity sets in [1–4].Comparison of experimental and simulation results reveal that our experimental findings are closely reproduced assuming a constant bulk lifetime after solar cell processing. Furthermore the results of this study were implemented in an optimized solar cell process. With 14Ω cm n-type Cz as base material solar cell efficiencies of up to 20.9% on 243.4cm2 (total area) were achieved which was confirmed by Fraunhofer ISE CalLab.