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

الأصل · EN

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.