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High-Performance and Traditional Multicrystalline Silicon: Comparing Gettering Responses and Lifetime-Limiting Defects

Abstract

In recent years, high-performance multicrystalline silicon (HPMC-Si) has emerged as an attractive alternative to traditional ingot-based multicrystalline silicon (mc-Si), with a similar cost structure but improved cell performance. Herein, we evaluate the gettering response of traditional mc-Si and HPMC-Si. Microanalytical techniques demonstrate that HPMC-Si and mc-Si share similar lifetime-limiting defect types but have different relative concentrations and distributions. HPMC-Si shows a substantial lifetime improvement after P-gettering compared with mc-Si, chiefly because of lower area fraction of dislocation-rich clusters. In both materials, the dislocation clusters and grain boundaries were associated with relatively higher interstitial iron point-defect concentrations after diffusion, which is suggestive of dissolving metal-impurity precipitates. The relatively fewer dislocation clusters in HPMC-Si are shown to exhibit similar characteristics to those found in mc-Si. Given similar governing principles, a proxy to determine relative recombination activity of dislocation clusters developed for mc-Si is successfully transferred to HPMC-Si. The lifetime in the remainder of HPMC-Si material is found to be limited by grain-boundary recombination. To reduce the recombination activity of grain boundaries in HPMC-Si, coordinated impurity control during growth, gettering, and passivation must be developed.

Category

Academic article

Language

English

Author(s)

  • Sergio Castellanos
  • Kai Erik Ekstrøm
  • Antoine Autruffe
  • Mallory A. Jensen
  • Ashley E. Morishige
  • Jasmin Hofstetter
  • Patricia Yen
  • Barry Lai
  • Gaute Stokkan
  • Carlos del Cañizo
  • Tonio Buonassisi

Affiliation

  • Massachusetts Institute of Technology (MIT)
  • Norwegian University of Science and Technology
  • Argonne National Laboratory
  • SINTEF Industry / Sustainable Energy Technology
  • Technical University of Madrid

Year

2016

Published in

IEEE Journal of Photovoltaics

ISSN

2156-3381

Volume

6

Issue

3

Page(s)

632 - 640

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