Silicon-based electroluminescent polycrystalline Er-doped Yb3Al5O12 nanofilms fabricated by atomic layer deposition

By virtue of the sub-nanometer compositional regulation realized via atomic layer deposition, polycrystalline Er-doped Yb3Al5O12 (YbAG:Er) garnet nanofilms are fabricated on silicon after annealing above 1100 degrees C. The crystalline feature is insensitive to slight deviation from the stoichiometric ratio (Yb:Al = 3:5 for Yb3Al5O12). The nanolaminate devices based on YbAG:Er films present Er-related 1531 nm electroluminescence exhibiting the external quantum efficiency of 2.7-5.2% and the power efficiency of 2.4-4.8 x 10(-4), whose fluorescence lifetime is estimated as 1-1.2 ms. The doped Er3+ ions are impact-excited by hot electrons stemming from Fowler-Nordheim tunneling mechanism within the Yb3Al5O12 matrix. This work is believed to lay the basis for manipulating multi-oxide nanofilms with designed composition and crystallinity, and developing optoelectronic devices from Si-based crystalline garnet films. (c) 2020 Elsevier B.V. All rights reserved.