Blue Electroluminescent Al(2)O(3)/Tm(2)O(3) Nanolaminate Films Fabricated by Atomic Layer Deposition on Silicon

Realization of a silicon-based light source is of significant importance for the future development of optoelectronics and telecommunications. Here, nanolaminate Al(2)O(3)/Tm(2)O(3) films are fabricated on silicon utilizing atomic layer deposition, and intense blue electroluminescence (EL) from Tm(3+) ions is achieved in the metal-oxide-semiconductor structured luminescent devices based on them. Precise control of the nanolaminates enables the study on the influence of the Tm dopant layers and the distance between every Tm(2)O(3) layer on the EL performance. The 456 nm blue EL from Tm(3+) ions shows a maximum power density of 0.15 mW/cm(2). The EL intensities and decay lifetime decrease with excessive Tm dopant cycles due to the reduction of optically active Tm(3+) ions. Cross-relaxation among adjacent Tm(2)O(3) dopant layers reduces the blue EL intensity and the decay lifetime, which strongly depends on the Al(2)O(3) sublayer thickness, with a critical value of ~3 nm. The EL is attributed to the impact excitation of the Tm(3+) ions by hot electrons in Al(2)O(3) matrix via Poole–Frenkel mechanism.