Ferromagnetism and Near-infrared Luminescence in Neodymium and Erbium Doped Gallium Nitride via Diffusion

Abstract

In this study, we report on the diffusion of neodymium (Nd) and erbium (Er) into n-type and undoped GaN and subsequent measurements of the room-temperature (RT) magnetic and optical properties. The diffusion profile has been measured via secondary ion mass spectroscopy (SIMS) with rare-earth (RE) concentration yields of up to 1x10 18 /cm 3 . The ferromagnetic properties were measured using an alternating gradient magnetometer (AGM) giving a saturation magnetization (Ms) of up to 3.17emu/cm 3 for the RE-diffused layer. The photoluminescence (PL) emission of the Nd-diffused and Er-diffused GaN is observable in the near-infrared (NIR) and infrared (IR) regions of the spectrum, respectively. The Nd-diffused GaN samples show NIR emission at 1064nm and 1350nm, while Er-diffused GaN samples have IR emission at 1546nm. This appears to be the first successful result of Nd diffusion doping into GaN crystals, and the first demonstration of above RT ferromagnetism involving GaN diffused with Nd. Details of our ferromagnetic and optical emission studies, related to the RE diffusion into GaN, are presented.

Dilute Magnetic III-N Semiconductors Based on Rare Earth Doping

“…Luen et al investigated the thermal diffusion of several different RE elements into GaN thin films including Nd. 41,42 GaN layers, including undoped GaN, p-GaN:Mg, and n-GaN:Si, were grown by MOCVD on sapphire substrates to serve as templates for the Nd diffusion experiments. Optimization of the diffusion conditions led to successful incorporation of Nd into the GaN films as evidenced by SIMS.…”

“…M vs H a hysteresis curves measured at RT for Nd diffused into: p-GaN:Mg; n-GaN:Si; and, undoped Ud-GaN. Diffusion into a doped substrate increased Ms 41.…”