Date

2013

Document Type

Dissertation

Degree

Doctor of Philosophy

Department

Physics

First Adviser

Stavola, Michael J.

Other advisers/committee members

DeLeo, Gary; Dierolf, Volkmar; Fowler, W. B.; Tatic-Lucic, Svetlana

Abstract

Light element impurities in multi-crystalline Si have been investigated with Fourier transform infrared spectroscopy. These experiments include defect studies in silicon with a high concentration of carbon and also with various concentrations of both nitrogen and oxygen.A thermally stable VH4 center trapped by carbon was discovered. The vibrational properties of this defect have been studied for the case of mixed H and D isotopes to establish its structure. The new lines we have found are assigned to the Si-H(D) and C-H(D) stretching modes of the defect center.We have studied N- and O-related defects in multi-crystalline Si used by industry to fabricate solar cells. The N-N center is the dominant N-related defect. However, N is also found to be bonded with O in multi-crystalline Si. NN-On centers are most likely seen when the oxygen concentration in the sample is high. We have also studied the properties of electrically active N-O centers that contain a single N atom. These N-O shallow donors are found to be present in multi-crystalline Si samples containing oxygen and nitrogen but with a lower concentration than is present in oxygen-rich Czochralski-grown Si that contains nitrogen.

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