Entity

Time filter

Source Type

Pue., Mexico

Morales-Sanchez A.,National Institute of Astrophysics, Optics and Electronics | Barreto J.,CSIC - National Center of Microelectronics | Dominguez C.,CSIC - National Center of Microelectronics | Aceves-Mijares M.,National Institute of Astrophysics, Optics and Electronics | And 3 more authors.
Nanotechnology | Year: 2010

Electroluminescent properties of silicon-rich oxide(SRO) films were studied using metal oxide semiconductor-(MOS)-like devices. Thin SRO films with 4at.% of silicon excess were deposited by low pressure chemical vapour deposition followed by a thermal annealing at 1100 °C. Intense continuous visible and infrared luminescence has been observed when devices are reversely and forwardly bias, respectively. After an electrical stress, the continuous electroluminescence (EL) is quenched but devices show strong field-effect EL with pulsed polarization. A model based on conductive paths - across the SRO film - has been proposed to explain the EL behaviour in these devices. © 2010 IOP Publishing Ltd. Source


Cabanas-Tay S.A.,CIDS BUAP | Palacios-Huerta L.,CIDS BUAP | Luna-Lopez J.A.,CIDS BUAP | Aceves-Mijares M.,National Institute of Astrophysics, Optics and Electronics | And 3 more authors.
Semiconductor Science and Technology | Year: 2015

An analysis of the luminescent center and its effect on the optical, electrical and electro-optical properties of silicon rich silicon nitride (SRN) films deposited by low pressure chemical vapor deposition is reported. As-deposited SRN films emit a broad photoluminescence (PL) spectrum in the visible range where the maximum peak shifts from ∼490 to ∼590 nm as the silicon excess increases. After thermal annealing, a PL blue-shift is observed and it is ascribed to a compositional-dependent change in the concentration of defect states within the films. A correlation between the PL peak energy with the optical band-gap indicates that the luminescence is related to the band tail carrier recombination in the SRN films. Light emitting capacitors (LECs) based on fluor-doped tin oxide SnO2:F (FTO)/SRN active layer/n-Si substrate emit a broad electroluminescent spectra where the maximum emission peak blue-shifts when the polarity is changed from reverse to forward bias. In the reverse bias, the electroluminescence (EL) is related to the states of valence band tail and Si dangling bonds (K0 centers), while in the forward bias the EL is originated from electronic transitions from the conduction band minimum to K0 centers. A model based on the trap assisted tunneling carrier transport is correlated with the proposed EL radiative recombination process in the FTO/SRN/n-Si structures. A discussion of the differences between the PL and EL spectra is reported. The results open new alternatives toward the development of Si-based light emitters where two different EL spectra can be obtained changing the polarity. © 2015 IOP Publishing Ltd. Source


Morales-Sanchez A.,National Institute of Astrophysics, Optics and Electronics | Barreto J.,CSIC - National Center of Microelectronics | Dominguez C.,CSIC - National Center of Microelectronics | Aceves M.,National Institute of Astrophysics, Optics and Electronics | And 4 more authors.
Materials Science and Engineering B: Solid-State Materials for Advanced Technology | Year: 2010

Electroluminescent properties of silicon nanoparticles embedded in MOS devices have been studied. Silicon rich oxide (SRO) films with 4 at.% of silicon excess were used as active layers. Intense and stable light emission is observed with the naked eye as shining spots at the surface of devices. AFM measurements on these devices exhibit a remarkably granular surface where the EL spots are observed. The EL measurements show a broad visible spectrum with various peaks between 420 and 870 nm. These EL spots are related with charge injection through conductive paths created by adjacent Si-nps within the SRO. © 2010 Elsevier B.V. All rights reserved. Source


Palacios-Huerta L.,CIDS BUAP | Cabanas-Tay S.A.,CIDS BUAP | Luna-Lopez J.A.,CIDS BUAP | Aceves-Mijares M.,National Institute of Astrophysics, Optics and Electronics | And 2 more authors.
Nanotechnology | Year: 2015

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. © 2015 IOP Publishing Ltd. Source


Morales-Sanchez A.,National Institute of Astrophysics, Optics and Electronics | Leyva K.M.,National Institute of Astrophysics, Optics and Electronics | Aceves M.,National Institute of Astrophysics, Optics and Electronics | Barreto J.,CSIC - National Center of Microelectronics | And 4 more authors.
Materials Science and Engineering B: Solid-State Materials for Advanced Technology | Year: 2010

Photoluminescence (PL) properties of thin and thick silicon-rich oxide (SRO) and silicon implanted SRO (SI-SRO) films with different silicon excess fabricated by low pressure chemical vapor deposition (LPCVD) were studied. The effects of the annealing temperature and silicon implantation on the PL were also studied. Maximum luminescence intensity was observed with an annealing temperature of 1150 and 1100 °C for thin and thick SRO films, respectively. The PL intensity is strongly enhanced when SRO films are implanted with silicon, especially for thin SRO films. Thin SI-SRO films emit up to six times more than non-implanted films, meanwhile the PL in thick SI-SRO films is only improved less than two times. Therefore, thin SI-SRO films are an interesting alternative for applications such as the fabrication of efficient Si-nps based LEDs. © 2010 Elsevier B.V. All rights reserved. Source

Discover hidden collaborations