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

P. Zheng, F. E. Rougieux, C. Samundsett, Xinbo Yang, Yimao Wan, J. Degoulange, R. Einhaus, P. Rivat, D. Macdonald

Research output: Contribution to journalArticlepeer-review

21 Scopus citations

Abstract

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.

Original languageEnglish (US)
Article number122103
JournalApplied Physics Letters
Volume108
Issue number12
DOIs
StatePublished - Mar 21 2016

ASJC Scopus subject areas

  • Physics and Astronomy (miscellaneous)

Fingerprint Dive into the research topics of 'Upgraded metallurgical-grade silicon solar cells with efficiency above 20%'. Together they form a unique fingerprint.

Cite this