The structure, electronic, magnetic and optical properties of the Co-X (X = B, C, N, O or F) codoped single-layer WS2

We use the first-principle methods to systematically study the structural, electronic, magnetic and optical characteristics of the perfect and Co-X (X = B, C, N, O or F) codoped single-layer WS₂. The results show that firstly, all Co-X (X = B, C, N, O or F) codoped single-layer WS₂ are easier to form in S-rich environment than in W-rich environment. Second, although the perfect single-layer WS₂ is non-magnetic semiconductor (NM-SC), the Co-X (X = B, C, N or F) codoped single-layer WS₂ become to magnetic semiconductor (M − SC) with magnetic moments 2, 3, 2 or 2 ${\mu }_{\text{B}}$, while the Co–O codoped single-layer WS₂ transforms to magnetic half metal (M-HM) with magnetic moment 1 ${\mu }_{\text{B}}$. Thirdly, comparing with the perfect single-layer WS₂, the Co-X (X = B, C, N, O or F) codoped single-layer WS₂ show not only the red-shifted absorption edges but also enhanced absorption rate in infrared and visible light region, implying the Co-X (X = B, C, N, O or F) codoped single-layer WS₂ have great application prospects in infrared and visible light detection.