Upgraded metallurgical-grade silicon solar cells with efficiency above 20%

Journal Article · Mon Mar 21 04:00:00 EDT 2016 · Applied Physics Letters

DOI:https://doi.org/10.1063/1.4944788· OSTI ID:22591468

Zheng, P.; Rougieux, F. E.; Samundsett, C.; Yang, Xinbo; Wan, Yimao; Macdonald, D. ^[1]; Degoulange, J.; Einhaus, R. ^[2]; Rivat, P. ^[3]

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1. Research School of Engineering, College of Engineering and Computer Science, The Australian National University, Canberra, Australian Capital Terrritory 2601 (Australia)
2. Apollon Solar, 66 Cours Charlemagne, Lyon 69002 (France)
3. FerroPem, 517 Avenue de la Boisse, Chambery Cedex 73025 (France)

We present solar cells fabricated with n-type Czochralski–silicon wafers grown with strongly compensated 100% upgraded metallurgical-grade feedstock, with efficiencies above 20%. The cells have a passivated boron-diffused front surface, and a rear locally phosphorus-diffused structure fabricated using an etch-back process. The local heavy phosphorus diffusion on the rear helps to maintain a high bulk lifetime in the substrates via phosphorus gettering, whilst also reducing recombination under the rear-side metal contacts. The independently measured results yield a peak efficiency of 20.9% for the best upgraded metallurgical-grade silicon cell and 21.9% for a control device made with electronic-grade float-zone silicon. The presence of boron-oxygen related defects in the cells is also investigated, and we confirm that these defects can be partially deactivated permanently by annealing under illumination.

• OSTI ID: 22591468
• Journal Information: Applied Physics Letters, Journal Name: Applied Physics Letters Journal Issue: 12 Vol. 108; ISSN APPLAB; ISSN 0003-6951
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ANNEALING
BORON
DEFECTS
DIFFUSION
EFFICIENCY
GETTERING
ILLUMINANCE
METALS
OXYGEN
PEAKS
PHOSPHORUS
RECOMBINATION
SILICON SOLAR CELLS
SUBSTRATES
SURFACES