Room Temperature GaN-based Spin Polarized Emitters

Wide band gap dilute magnetic semiconductors have recently been of interest due to theoretical predictions of room temperature ferromagnetism in these materials. In this work Ga1-xGdxN thin films were grown by Metalorganic Chemical Vapor Deposition. These films were found to be ferromagnetic at room temperature and electrically conducting. However, only GaN:Gd layers and devices grown with a TMHD3Gd precursor that contained oxygen showed strong ferromagnetism, while materials grown with an oxygen-free Cp3Gd precursor did not show ferromagnetic behavior. This experimental observation was consistent with first-principles calculations based on density functional theory calculations that we completed that showed the ferromagnetism was mediated by interstitial oxygen. The results confirmed the first successful realization of Ga1-xGdxN-based spin-polarized LED with 14.6% degree of polarization at 5000 Gauss is obtained.