Efficient spin-light emitting diodes based on InGaN/GaN quantum disks at room temperature: a new self-polarized...

Area of Science:

• Semiconductor Spintronics
• Optoelectronics
• Materials Science

Background:

• Nitride semiconductors exhibit weak spin polarization due to limited spin-orbit interaction.
• Developing efficient spin-light emitting devices is crucial for advanced spintronics applications.
• Existing methods struggle to achieve high spin polarization at room temperature.

Purpose of the Study:

• To design and fabricate a high-performance spin-light emitting diode (LED).
• To investigate mechanisms enhancing spin polarization in InGaN/GaN based devices.
• To overcome limitations of low spin polarization in nitride semiconductors.

Main Methods:

• Fabrication of an InGaN/GaN multiple quantum disk (MQD) LED with ferromagnetic contacts and Fe3O4 nanoparticles.
• Characterization of electroluminescence (EL) and its circular polarization under magnetic fields.
• Analysis of spin-polarized electron and hole transfer and spin relaxation mechanisms.

Main Results:

• Achieved a high degree of circular polarization (10.9%) at room temperature with a low magnetic field (0.35 T).
• Demonstrated selective spin transfer via Fe3O4 nanoparticles filling inter-nanodisk vacancies.
• Observed weak temperature dependence of spin relaxation and enhanced spin relaxation time due to strain relaxation.

Conclusions:

• The designed InGaN/GaN MQD LED significantly enhances output spin polarization.
• The integration of half-metal nanoparticles and nanodisk structure offers a novel route for high-performance spintronic devices.
• This approach provides a new direction for research and development in semiconductor spintronics.