Spin Electronics: A new Spin for the Nitrides: Can Room Temperature Ferromagnetism be obtained in (Ga,Mn)N?

Georgia Tech Research Corporation, Atlanta GA

Investigators

Abstract

This proposal was received in response to the Spin Electronics for the 21st Century Initiative, Program Solicitation NSF 02-036. The proposal focuses on the development of a room temperature ferromagnetic compound semiconductor material, Ga1-xMnxN, for spintronic devices based on the spin property of electrons. Many advances have been made in developing the materials and devices for III-V compound semiconductor materials doped with manganese (Mn), with Ga1-xMnxAs showing the most promise. However, the low Curie temperatures (Tc) for these materials require potential devices to be operated at temperatures below 77K. There is a need to produce a new class of materials that can operate at, or near, room temperature to facilitate the ease of measurement and the eventual commercialization of this technology. The III-Nitrides will be excellent for this application because recent theoretical predictions show that Ga1-xMnxN could have Tc higher than room temperature. The Ga1-xMnxN can also be integrated into existing base of microelectronics or optoelectronics existing for GaN-based devices. In this work it is proposed to produce Ga1-xMnxN by Metalorganic Chemical Vapor Deposition, the growth technique of choice for GaN based devices. There are no published reports of the growth of Ga1-xMnxN by this growth technique at this time. A systematic study of the growth of Ga1-xMnxN will be completed. Detailed characterization of the physical properties Ga1-xMnxN will be investigated using x-ray analysis, Hall measurements, time resolved photoluminescence, and other techniques. A novel Ga1-xMnxN/Ga1-xAlxN/Ga1-xInxN LED structure will be grown so that spin injection can easily be investigated at room temperature. The broader impact of this work is clear: Spintronic devices that can be operated at or near room temperature will be required if quantum computing based on compound semiconductor materials is going to have a commercial viability in the future.