Atomic-scale distribution of impurities in CuInSe2-based thin-film solar cells

O Cojocaru-Mirédin; P Choi; R Wuerz; D Raabe

doi:10.1016/j.ultramic.2010.12.034

Atomic-scale distribution of impurities in CuInSe2-based thin-film solar cells

Ultramicroscopy. 2011 May;111(6):552-6. doi: 10.1016/j.ultramic.2010.12.034. Epub 2011 Jan 11.

Authors

O Cojocaru-Mirédin¹, P Choi, R Wuerz, D Raabe

Affiliation

¹ Max-Planck-Institut für Eisenforschung, Max-Planck-Straße 1, 40237 Düsseldorf, Germany.

PMID: 21288643
DOI: 10.1016/j.ultramic.2010.12.034

Abstract

Atom Probe Tomography was employed to investigate the distribution of impurities, in particular sodium and oxygen, in a CuInSe(2)-based thin-film solar cell. It could be shown that sodium, oxygen, and silicon diffuse from the soda lime glass substrate into the CuInSe(2) film and accumulate at the grain boundaries. Highly dilute concentrations of sodium and oxygen were measured in the bulk. Selenium was found to be depleted at the grain boundaries. These observations could be confirmed by complementary energy dispersive X-ray spectroscopy studies. Our results support the model proposed by Kronik et al. (1998) [1], which explains the enhanced photovoltaic efficiency of sodium containing CuInSe(2) solar cells by the passivation of selenium vacancies at grain boundaries.