title: Effect of the structure on luminescent characteristics of SRO-based light emitting capacitors.
abstract: In this paper, we study the structural, optical and electro-optical properties of silicon rich oxide (SRO) films, with 6.2 (SRO₃₀) and 7.3 at.% (SRO₂₀) of silicon excess thermally annealed at different temperatures and used as an active layer in light emitting capacitors (LECs). A typical photoluminescence (PL) red-shift is observed as the silicon content and annealing temperature are increased. Nevertheless, when SRO₃₀ films are used in LECs, a resistance switching (RS) behavior from a high current state (HCS) to a low conduction state (LCS) is observed, enhancing the intense blue electroluminescence (EL). This RS produces a long spectral blue-shift (∼227 nm) between the EL and PL band, and it is related to structural defects created by a high current flow through preferential conductive paths breaking off Si-Si bonds from very small silicon nanoparticles (Si-nps) (Eδ (Si ↑ Si ≡ Si) centers). LECs with SRO₂₀ films do not present the RS behavior and only exhibit a slight shift between PL and EL, both in red spectra. The carrier transport in these LEC devices is analyzed as being trap assisted tunnelling and Poole-Frenkel through a quasi 'continuum' of defect traps and quantum dots for the conduction mechanism in SRO₃₀ and SRO₂₀ films, respectively. The results prove the feasibility of obtaining light emitting devices by using simple panel structures with Si-nps embedded in the dielectric layer.
authors.affiliation: CIDS-BUAP, Apdo. 1651, Puebla, Pue. 72000, México.
authors.forename: L
authors.initials: L
authors.lastname: Palacios-Huerta
authors.forename: S A
authors.initials: SA
authors.lastname: Cabañas-Tay
authors.forename: J A
authors.initials: JA
authors.lastname: Luna-López
authors.forename: M
authors.initials: M
authors.lastname: Aceves-Mijares
authors.forename: A
authors.initials: A
authors.lastname: Coyopol
authors.forename: A
authors.initials: A
authors.lastname: Morales-Sánchez