Study of structural and electronic properties of the silanone group as bulk defect in amorphous SiO2

•The existence of the silanone group as bulk defect in amorphous SiO2 is theoretically proved.•The SiO bond length of the silanone group as bulk defect in amorphous SiO2 is 1.5275 Å.•The silanone group as bulk defect in amorphous SiO2 is stable until the temperature exceeds 900 K.•The SG defect forms new electronic state distribution and reduces width of the band gap.

The paper studies the structural, thermo- and electronic properties of the silanone group (SG, oxygen double-bond) as bulk defect of amorphous SiO2 (a-SiO2), whose supercell consists of 108 atoms, and the molecular dynamics and first principle calculations are used. The results theoretically prove the existence and good thermo-stability of SG as bulk defect in a-SiO2. Besides, the electronic density of states (DOS) and orbital-resolved partial DOS (PDOS) are studied as well. The results show that new electronic state distribution in the band gap of a-SiO2 is found, as well as reduced width of the band gap, which are produced by the SG defect.