Electronic structure and energy landscape of <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:msub><mml:mi mathvariant="normal">B</mml:mi><mml:mi>Si</mml:mi></mml:msub><mml:msub><mml:mi>Si</mml:mi><mml:mi>i</mml:mi></mml:msub><

Boron is an important dopant for silicon. Together with an adjacent interstitial Si atom, it forms the so-called <a:math xmlns:a="http://www.w3.org/1998/Math/MathML"><a:mrow><a:msub><a:mi mathvariant="normal">B</a:mi><a:mi>Si</a:mi></a:msub><a:msub><a:mi>Si</a:mi><a:mi>i</a:mi></a:msub></a:mrow></a:math> defect, which has been proposed as a source of light-induced degradation (LID) in solar cells made from boron-doped Czochralski-grown silicon. Furthermore, the <c:math xmlns:c="http://www.w3.org/1998/Math/MathML"><c:mrow><c:msub><c:mi mathvariant="normal">B</c:mi><c:mi>Si</c:mi></c:msub><c:msub><c:mi>Si</c:mi><c:mi>i</c:mi></c:msub></c:mrow></c:math> defect is an intermediate configuration in many models for boron diffusion in silicon. In the present comprehensive density-functional-theory-based study, we have calculated the energy landscape around the <e:math xmlns:e="http://www.w3.org/1998/Math/MathML"><e:mrow><e:msub><e:mi mathvariant="normal">B</e:mi><e:mi>Si</e:mi></e:msub><e:msub><e:mi>Si</e:mi><e:mi>i</e:mi></e:msub></e:mrow></e:math> defect and related defects involving one B atom and one interstitial Si atom for different chemical potentials of electrons corresponding to neutral, positively, and negatively charged supercells. Among the found metastable defect configurations, we identify possible recombination centers based on the defect-dependent electronic density of states and the minimal energy paths between them. The resulting potential energy landscape is checked against empirical models for boron diffusion and LID.