Enhancement of the Electroluminescence from Amorphous Er-Doped Al₂O₃ Nanolaminate Films by Y₂O₃ Cladding Layers Using...

Amorphous Al₂O₃-Y₂O₃:Er nanolaminate films are fabricated on silicon by atomic layer deposition, and ~1530 nm electroluminescence (EL) is obtained from the metal-oxide-semiconductor light-emitting devices based on these nanofilms. The introduction of Y₂O₃ into Al₂O₃ reduces the electric field for Er excitation and the EL performance is significantly enhanced, while the electron injection of devices and the radiative recombination of doped Er³⁺ ions are not impacted. The 0.2 nm Y₂O₃ cladding layers for Er³⁺ ions increase the external quantum efficiency from ~3% to 8.7% and the power efficiency is increased by nearly one order of magnitude to 0.12%. The EL is ascribed to the impact excitation of Er³⁺ ions by hot electrons, which stem from Poole-Frenkel conduction mechanism under sufficient voltage within the Al₂O₃-Y₂O₃ matrix.