# Hydrogen/nitrogen/oxygen defect complexes in silicon from computational searches

**Authors:** Andrew J. Morris, Chris J. Pickard, R. J. Needs  
**arXiv:** [0908.1658](https://arxiv.org/abs/0908.1658)  
**Date:** 2009-08-12  
**Summary page:** https://www.summarizepaper.com/en/paper/0908.1658v1/

## Abstract

Point defect complexes in crystalline silicon composed of hydrogen, nitrogen, and oxygen atoms are studied within density-functional theory (DFT). Ab initio Random Structure Searching (AIRSS) is used to find low-energy defect structures. We find new lowest-energy structures for several defects: the triple-oxygen defect, {3O}, triple oxygen with a nitrogen atom, {N, 3O}, triple nitrogen with an oxygen atom, {3N,O}, double hydrogen and an oxygen atom, {2H,O}, double hydrogen and oxygen atoms, {2H,2O} and four hydrogen/nitrogen/oxygen complexes, {H,N,O}, {2H,N,O}, {H,2N,O} and {H,N,2O}. We find that some defects form analogous structures when an oxygen atom is replaced by a NH group, for example, {H,N,2O} and {3O}, and {H,N} and {O}. We compare defect formation energies obtained using different oxygen chemical potentials and investigate the relative abundances of the defects.