Spin-dependent recombination in Czochralski silicon containing oxide precipitates

TL;DR

This study uses electrically detected magnetic resonance to identify spin-dependent recombination centers in Czochralski silicon with oxide precipitates, revealing how precipitate density influences recombination rates and highlighting the technique's effectiveness in photovoltaic materials.

Contribution

The paper demonstrates the application of electrically detected magnetic resonance to analyze spin-dependent recombination in silicon with oxide precipitates, providing new insights into recombination mechanisms.

Findings

Recombination occurs via Pb0 and Pb1 dangling bonds at surfaces and precipitates.

Recombination rates increase linearly with precipitate density.

Iron-related resonance lines are observed and discussed.

Abstract

Electrically detected magnetic resonance is used to identify recombination centers in a set of Czochralski grown silicon samples processed to contain strained oxide precipitates with a wide range of densities (~ 1e9 cm-3 to ~ 7e10 cm-3). Measurements reveal that photo-excited charge carriers recombine through Pb0 and Pb1 dangling bonds and comparison to precipitate-free material indicates that these are present at both the sample surface and the oxide precipitates. The electronic recombination rates vary approximately linearly with precipitate density. Additional resonance lines arising from iron-boron and interstitial iron are observed and discussed. Our observations are inconsistent with bolometric heating and interpreted in terms of spin-dependent recombination. Electrically detected magnetic resonance is thus a very powerful and sensitive spectroscopic technique to selectively probe recombination centers in modern photovoltaic device materials.