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

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 N 2− ions in addition to N 3− ions, and N 2− 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 N 2− 2p states. In comparison with the Ga 34 MN 36 (M = Be/Ca) system, the magnetic moments of Ga 34 MH i N 36 (M = Be/Ca) system are reduced after doping with H i interstitial. The magnetic properties of the Ga 34 MgN 36 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 Ga 34 MgH i N 36 system extends to the mid-infrared optical region. This material has some reference value as infrared thermophotovoltaic cells, infrared photodetectors, or infrared semiconductor lasers.