An investigation of vacancy defects on electronic and magnetic properties of TlN nanosheet: By density function calculation

Abstract Infrared photodetectors have gained attention because of its high penetration depth of IR light. Narrow band gap semiconductors can function as photoactive materials in IR photodetector applications. Herein, a the TlN nanosheet is proposed because the TlN nanosheet has narrow band gap and the TlN nanosheet with vacancy defect is a good candidate for spintronic applications. Under the generalized gradient approximation (GGA), the vacancy defects on electronic and magnetic properties of semiconductor the TlN (thallium nitride) nanosheet have been investigated by full potential linearized augmented plane wave method (FP-LAPW) within the density function theory (DFT) implemented by the Wien2k code. The electronic band structure calculations indicate that Tl atom vacancy (VTl), N atom vacancy (VN) in the 2D TlN nanosheet leads to p-type and n-type conductivity, respectively. And mixed Tl and N atoms (VTl&N) vacancies maintain the overall neutral charge in the solid. We found that the vacancies in the TlN nanosheet induce spin polarized states in the band gap, and VTl-defect, VN-defect and VTl&N-defect induce local magnetic moments of 3.0μB, 0.3μB and 3.8μB, respectively.