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

Amorphous Al2O3-Y2O3:Er nanolaminate films are fabricated on silicon by atomic layer deposition, and similar to 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 similar to 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.