First-principles study on the effect of point defects on the magnetic new mechanism and optical properties of the GaN:Be/Mg/Ca system

Abstract

The new magnetic mechanism and optical properties of Ga vacancies and H_i interstitial in the GaN: Be/Mg/Ca system have not been fully understood, and the use of first principles can solve this problem. The effect of point defects on the magnetic mechanism and optical properties of the GaN: Be/Mg/Ca system was investigated using the first nature principle of the hybridized generalized HSE06 method. Results show that all doped systems have N²⁻ ions in addition to N³⁻ ions, and N²⁻ ions have the dual property of itinerant electrons in the off-domain (donor) and of local electrons (acceptor). The magnetism of magnetic doped systems is generated by the hybrid coupling of Ga4s and N²⁻ 2p states. In comparison with the Ga₃₄MN₃₆ (M = Be/Ca) system, the magnetic moments of Ga₃₄MH_iN₃₆ (M = Be/Ca) system are reduced after doping with H_i interstitial. The magnetic properties of the Ga₃₄MgN₃₆ system can be regulated by the presence or absence of H_i interstitial, which is advantageous as a magnetic switch. The absorption spectral distribution of the Ga₃₄MgH_iN₃₆ system extends to the mid-infrared optical region. This material has some reference value as infrared thermophotovoltaic cells, infrared photodetectors, or infrared semiconductor lasers.