Blue Electroluminescence in SRO-HFCVD Films

Abstract

In this work, electroluminescence in Metal-Insulator-Semiconductors (MIS) and Metal-Insulator-Metal (MIM)-type structures was studied. These structures were fabricated with single- and double-layer silicon-rich-oxide (SRO) films by means of Hot Filament Chemical Vapor Deposition (HFCVD), gold and indium tin oxide (ITO) were used on silicon and quartz substrates as a back and front contact, respectively. The thickness, refractive indices, and excess silicon of the SRO films were analyzed. The behavior of the MIS and MIM-type structures and the effects of the pristine current-voltage (I-V) curves with high and low conduction states are presented. The structures exhibit different conduction mechanisms as the Ohmic, Poole–Frenkel, Fowler–Nordheim, and Hopping that contribute to carrier transport in the SRO films. These conduction mechanisms are related to the electroluminescence spectra obtained from the MIS and MIM-like structures with SRO films. The electroluminescence present in these structures has shown bright dots in the low current of 36 uA with a voltage of −20 V to −50 V. However, when applied voltages greater than −67 V with 270 uA, a full area with uniform blue light emission is shown.

Nanocomposites of Silicon Oxides and Carbon: Its Study as Luminescent Nanomaterials

“…A material of great technological interest in silicon optoelectronic research is silicon-rich oxide (SRO), which has been reported on multiple occasions as a material with nanostructures intrinsically formed within it. An outstanding characteristic of the SRO is that it facilitates the formation of silicon nanocrystals (Si-ncs) embedded in a SiO 2 matrix [ 7 ], where electron quantum confinement is generated due to low-dimensional effects, leading to an efficient light emission [ 8 ]. Apart from the effects related to quantum confinement in nanostructures, it has been reported the presence of intrinsic defects in the SRO films that favor the radiative emission [ 9 , 10 ].…”