Ferromagnetic and multiferroic thin films aimed towards optoelectronic and spintronic applications

Ferromagnetic;Thin films;Gadolinium;GaN;Spintronic;Spin-LED;LED

Zaidi, Tahir ; Electrical and Computer Engineering

University:Georgia Institute of Technology

Department:Electrical and Computer Engineering

关键词: Ferromagnetic;    Thin films;    Gadolinium;    GaN;    Spintronic;    Spin-LED;    LED;   

Others  :  https://smartech.gatech.edu/bitstream/1853/41110/1/zaidi_tahir_201005_phd.pdf

美国|英语

来源: SMARTech Repository

【 摘 要 】

This work targeted the growth of gadolinium (Gd)-doped gallium nitride (GaN) thin films (Ga₁₋ₓGdₓN) by metal organic chemical vapor deposition (MOCVD). Characterization and evaluation of these Ga₁₋ₓGdₓN thin films for application in spintronics/optoelectronics devices also formed part of this work. This work presents: (1) the first report of stable, reproducible n- and p-type Ga₁₋ₓGdₓN thin films by MOCVD; (2) the first Ga₁₋ₓGdₓN p-n diode structure; and (3) the first report of a room temperature spin-polarized LED using a Ga₁₋ₓGdₓN spin injection layer. The Ga₁₋ₓGdₓN thin films grown in this work were electrically conductive, and co-doping them with Silicon (Si) or Magnesium (Mg) resulted in n-type and p-type materials, respectively. All the materials and structures grown in this work, including the Ga₁₋ₓGdₓN-based p-n diode and spin polarized LED, were characterized for their structural, optical, electrical and magnetic properties. The spin-polarized LED gave spin polarization ratio of 22% and systematic variation of this ratio at room temperature with external magnetic field was observed.