[A-6] III-V Light Sources

[A-6-05] Room-temperature operation characteristics of a spin-polarized light-emitting diode using InAs quantum dots tunnel-coupled with GaNAs

〇Kohei Etou¹, Satoshi Hiura¹, Junichi Takayama¹, Agus Subagyo¹, Kazuhisa Sueoka¹, Akihiro Murayama¹ (1. Faculty of Information Science and Technology, Hokkaido University (Japan))

Presentation style: On-site (in-person)

https://doi.org/10.7567/SSDM.2022.A-6-05

We have developed a spin-polarized light-emitting diode (spin LED) using InAs quantum dots (QDs) tunnel-coupled with a GaNAs quantum well, which can amplify the electron spin polarization in QDs at room temperature due to the thermally activated spin filtering in GaNAs. Since conduction band electrons are easily trapped in deep-level defects in GaNAs during LED operation, the introduction of GaNAs can significantly increase the injection current required to obtain a sufficient QD electroluminescence (EL). We also observe the high degree of EL circular polarization ranging from 5 to 6 % under high bias conditions above 4 V. This high spin polarization is due to the selective transfer of minority spins from QDs to GaNAs spin filter via electron wavefunction coupling.