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.