Properties Of Mn-doped GaN Research Articles

First-principles study on electromagnetic properties of Mn-doped GaN

The electrical and magnetic properties of Mn-doped GaN were investigated by the density functional theory of spin polarization. The results indicate that Mn-doped GaN is still a direct bandgap semiconductor, and the bandgap width increases with the increase of Mn content. The N 2p and Mn 3d orbital were hybridized, which produce the spin polarization impurity bands, and the spin up the band to occupy the Fermi surface. The Ga1-xMnxN exhibits the semi-metallic ferromagnetism, which is suitable for spin injection. With the increase of Mn doping concentration, the semi-metallic properties of the system are enhanced. The studied results show that Mn-doped GaN can be applied as the ideal spin electronic material.

Research on the Mn-implanted GaN with ferromagnetism at room temperature

The Mn-implanted GaN with ferromagnetism at room temperature has been prepared successfully. The optical and structural properties of Mn-implanted GaN films have been investigated. The films studied were grown by metal organic chemical vapor deposition, with Mn implanted in 150 keV, which can offer many distinguished advantages compared with other doping methods. A new energy band with a minimum at 2.9 eV in the reflectance spectra has been observed. The yellow band emission was greatly decreased according to the result of photoluminescence. The results of vibrating sample magnetometer experiment proved the ferromagnetic properties of Mn-doped GaN at room temperature.

Magnetic properties of Mn-doped GaN, InGaN, and AlGaN

ABSTRACTWe report on the growth and magnetic properties of single crystal Mn-doped GaN, InGaN, and AlGaN films. The III-Nitride films were grown by MOCVD, while the Mn doping was performed by solid-state diffusion of a surface Mn layer deposited by pulsed laser ablation. Mn-doped InxGa1-xN films were grown with x < 0.15, where the easy axis of magnetization rotates from in-plane to out-of-plane by changing the InxGa1-xN thickness/strain-state of the film from compressively strained to relaxed. Mn-doped AlxGa1-xN films were grown with x < 0.40 showing ferromagnetic behavior above room temperature. SQUID measurements ruled out superparamagnetism within these films. By optimizing the growth and annealing conditions of Mn-doped III-Nitrides, we have achieved Curie temperatures in the range of 228 to 500K. These ferromagnetic Mn-doped III-Nitride films exhibit hysteresis with a coercivity of 100–500 Oe. TEM analysis showed no secondary phases within these films.

Optical Study of GaN Doped with Mn Grown by Metal Organic Vapor Phase Epitaxy

ABSTRACTThe optical properties of Mn-doped GaN were investigated. The films were grown by metalorganic vapor phase epitaxy using tricarbonyl (methylcyclopentadienyl) manganese as the dopant source. Two characteristic bands were observed in the absorption spectra of Mn-doped epilayers. The low energy band had a threshold at 1.4 ± 0.05 eV with a maximum at 1.5 ± 0.02 eV, with a full width half maximum of 245 ± 10 meV at 296 K. A second higher energy band was observed as a shoulder to the band edge absorption with a threshold energy of 2.06 eV at room temperature. Using photoluminescence spectroscopy, a new broad band was observed in the infrared spectra of GaN:Mn at 1.27 ± 0.02 eV with a full width half maximum of 0.26 ± 0.01 eV at 20K. From analysis of optical absorption and emission spectra Mn forms a deep acceptor level with optical transitions at 1.4 and 2.06 eV. The deep level nature of Mn indicates that it is a potential dopant for semi-insulating GaN.