The spin-resolved electronic structure of the codoped crystals Si < B, V>, Si < B, Cr > and Si < B, Mn>.

First, we have evaluated the spin-resolved electronic structure of crystals Si < B, V>, Si < B, Cr > and Si < B, Mn > with the exchange-correlation energy in a form of generalized gradient approximation (GGA-PBE). Next, the strong correlation effects of the V, Cr and Mn 3d electrons have been taken into account by means of the hybrid exchange-correlation functional PBE0. All the calculations have been done for supercells Si30B1V1, Si30B1Cr1, and Si30B1Mn1, modeling the substitutional alloys based on silicon crystal. In the pseudogap materials we are considering here, the Fermi level lies in the valence band. Without taking into account the strong correlations of the 3d electrons of the transition elements, we found the following properties of the materials under study. For the spin up the SiBV has an indirect pseudogap, the SiBCr is a direct gap material, and the SiBMn is an indirect pseudogap material. For the spin down these materials are a direct gap, direct pseudogap and indirect gap materials, respectively. Taking into account the strong correlations of the 3d electrons of the transition elements, we found the following properties of these materials. For the spin up the SiBV and SiBCr are the direct gap materials and SiBMn has an indirect pseudogap. For the spin down the SiBV is a direct pseudogap material, and the SiBCr is an indirect pseudogap compound, and SiBMn has a direct band gap. [ABSTRACT FROM AUTHOR]