Different substitutions lead to differences in the transport and recombination properties of group V doped SiCNTs

Silicon carbide nanotubes (SiCNTs) has attractive application prospects in the field of micro-nanodevices. Based on first-principle, we find that a shallow and a deep impurity levels appearing when a group-V element replaces a C, while only one deep impurity level appears when a group-V replaces a Si. This indicates that different electronic properties will be generated when group-V replace different sites of SiCNTs. Further numerical simulation results show that when dopant replaces C, the conductivity is about an order of magnitude higher than dopant replaces Si, and the conductivity increase with increasing temperature; the non-equilibrium minority carrier lifetime decrease with increasing temperature, when group-V replace the C, they are strong n-type, when replace the Si, they are in weak n-type and strong p-type. These results will help reveal the doping mechanism of SiC nanomaterials and the selection of dopants, and provide a theoretical basis for the preparation of micro-nanodevices.