Development of room temperature spin polarised emitters

The mechanism leading to RT ferromagnetism in Gd-doped GaN is not well understood. Oxygen impurities have been proposed as a possible contributor to ferromagnetic behavior in Ga
1−x
Gd
x
N films but the physical mechanism is not clear. In this work, Ga
1−x
Gd
x
N thin films were grown by MOCVD using two different metalorganic Gd precursors (TMHD)
3
Gd and Cp
3
Gd. Samples grown with (TMHD)
3
Gd, which contains oxygen, exhibited much higher magnetic moments. Co-doping of the Ga
1−x
Gd
x
N films with Si produced conductive n-type material, while co-doping with Mg produced compensated p-type material. Si and Mg co-doped films exhibited room temperature ferromagnetism and this material was then incorporated into a room temperature spin-polarized LED. Electroluminescence from this device had a degree of polarization of 14.6% at 5000 Gauss and retained a degree of polarization of 9.3% after removal of the applied magnetic field.