Low threshold voltage blue light emitting diodes based on thulium doped gallium oxides

Thulium doped gallium oxides (Tm-Ga₂O₃) films were deposited on Si substrates by the pulsed laser deposition method. Blue emissions (476 nm and 460 nm) can be observed by the naked eye from Tm-Ga₂O₃/Si light emitting diodes (LEDs). The threshold voltage of Tm-Ga₂O₃/Si LEDs is 6.3 V, which is lower than that of Tm-GaN/Si devices. By combining our previously reported green emission from Er-Ga₂O₃ and red emission from Eu-Ga₂O₃, strong blue emission from Tm-Ga₂O₃ can realize the full-color LEDs with the single host of Ga₂O₃. These results open a pathway for integrating Ga₂O₃ based full-color LEDs with mainstream Si technology. (author)