The first principle study and experimental of boron synergistic sulfur doping in diamond

Abstract

In this paper, optical absorption spectrum, band structure and electrical structure of diamond doped with B,S are investigated by density functional theory (DFT).Comparing optical absorption spectra of diamond un-doped and doped with B, S, absorption band edge of type IIa and type Ib diamonds doped with B,S move toward long wavelength direction and there are an absorption coefficient at a wavelength greater than that at 400 nm. In addition, incorporation of B contribute to improvement of conductive properties of diamond doped with BS. At the same time, comparing density of state for diamond doped with B or B-S, it is found that S-3p, B-2s and B-2p contribute to conduction band. In summary, it can be considered that conductivity type of diamond with BS co-doped is n-type semiconductor, and with synergy of B, S is as a suitable shallow donor impurity in diamond. Furthermore, in order to confirm above calculation results, type IIa and type Ib large single crystal diamond doped with B, S are synthesized under FeNi-C system. The color change of diamond is consistent with results of diamond optical absorption spectrum in DFT. The electrical measurement results show that type IIa and type Ib diamond doped with B,S present n-type semiconductor characteristics. The incorporation of B contributes to the improvement of electrical properties of diamond doped with S.