Near-Infrared Electroluminescence Based on Nd-Doped Ga₂O₃ Nanolaminates Fabricated by Atomic Layer Deposition for Optoelectronic Applications

Near-infrared electroluminescence (EL) peaking at 1067 nm is achieved from the devices based on Ga2O3:Nd nanolaminates fabricated by atomic layer deposition on silicon. The emissions originating from intra-4f transitions in Nd3+ ions are activated by both forward and reverse biases, with an external quantum efficiency of ∼1% and the optical power density of 10.5 mW/cm2. The devices operate continuously for more than 4 h and exhibit fluctuant EL emission under alternating-current excitation. Such EL is triggered by the energetic electrons accelerated via interfacial SiOx or Al2O3/TiO2 nanolaminate layers. EL under unidirectional bias is obtained by using a 4 nm interfacial Al2O3 nanofilm that sustains the electric field and energizes injected electrons, demonstrating the acceleration of electrons by high resistance layers and the carrier conduction considering interface energy barrier is indispensable for efficient EL excitation. This work provides innovative nanofilms based on Nd-doped oxides with great potential for applications in Si-based photonics and integrated optoelectronics.