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Study of the Effect of Nitric Acid in Electrochemically Synthesized Silicon Nanocrystals: Tunability of Bright and Uniform Photoluminescence. NANOMATERIALS 2022; 12:nano12122015. [PMID: 35745354 PMCID: PMC9229415 DOI: 10.3390/nano12122015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/06/2022] [Revised: 06/06/2022] [Accepted: 06/07/2022] [Indexed: 11/17/2022]
Abstract
In this work, we show a correlation between the composition and the microstructural and optical properties of bright and uniform luminescent porous silicon (PSi) films. PSi films were synthesized by electrochemical etching using nitric acid in an electrolyte solution. PSi samples synthesized with nitric acid emit stronger (up to six-fold greater) photoluminescence (PL) as compared to those obtained without it. The PL peak is shifted from 630 to 570 nm by changing the concentration ratio of the HF:HNO3:(EtOH-H2O) electrolyte solution, but also shifts with the excitation energy, indicating quantum confinement effects in the silicon nanocrystals (Si-NCs). X-ray photoelectron spectroscopy analysis shows a uniform silicon content in the PSi samples that emit the strongest PL. High-resolution transmission electron microscopy reveals that the Si-NCs in these PSi samples are about ~2.9 ± 0.76 nm in size and are embedded in a dense and stoichiometric SiO2 matrix, as indicated by the Fourier transform infrared analysis. On the other hand, the PSi films that show PL of low intensity present an abrupt change in the silicon content depth and the formation of non-bridging oxygen hole center defects.
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Milliken S, Thiessen AN, Cheong IT, O'Connor KM, Li Z, Hooper RW, Robidillo CJT, Veinot JGC. "Turning the dials": controlling synthesis, structure, composition, and surface chemistry to tailor silicon nanoparticle properties. NANOSCALE 2021; 13:16379-16404. [PMID: 34492675 DOI: 10.1039/d1nr04701a] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Silicon nanoparticles (SiNPs) can be challenging to prepare with defined size, crystallinity, composition, and surface chemistry. As is the case for any nanomaterial, controlling these parameters is essential if SiNPs are to realize their full potential in areas such as alternative energy generation and storage, sensors, and medical imaging. Numerous teams have explored and established innovative synthesis methods, as well as surface functionalization protocols to control these factors. Furthermore, substantial effort has been expended to understand how the abovementioned parameters influence material properties. In the present review we provide a commentary highlighting the benefits and limitations of available methods for preparing silicon nanoparticles as well as demonstrations of tailoring optical and electronic properties through definition of structure (i.e., crystalline vs. amorphous), composition and surface chemistry. Finally, we highlight potential opportunities for future SiNP studies.
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Affiliation(s)
- Sarah Milliken
- Department of Chemistry, University of Alberta, Chemistry, Edmonton, Canada.
| | | | - I Teng Cheong
- Department of Chemistry, University of Alberta, Chemistry, Edmonton, Canada.
| | - Kevin M O'Connor
- Department of Chemistry, University of Alberta, Chemistry, Edmonton, Canada.
| | - Ziqi Li
- Department of Chemistry, University of Alberta, Chemistry, Edmonton, Canada.
| | - Riley W Hooper
- Department of Chemistry, University of Alberta, Chemistry, Edmonton, Canada.
| | | | - Jonathan G C Veinot
- Department of Chemistry, University of Alberta, Chemistry, Edmonton, Canada.
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Palacios-Huerta L, Cabañas-Tay SA, Luna-López JA, Aceves-Mijares M, Coyopol A, Morales-Sánchez A. Effect of the structure on luminescent characteristics of SRO-based light emitting capacitors. NANOTECHNOLOGY 2015; 26:395202. [PMID: 26360552 DOI: 10.1088/0957-4484/26/39/395202] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
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.
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Xu L, Li S, Jin L, Li D, Yang D. Temperature dependence of sensitized Er(3+) luminescence in silicon-rich oxynitride films. NANOSCALE RESEARCH LETTERS 2014; 9:489. [PMID: 25258608 PMCID: PMC4167255 DOI: 10.1186/1556-276x-9-489] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/25/2014] [Accepted: 09/07/2014] [Indexed: 06/03/2023]
Abstract
The temperature dependence of sensitized Er(3+) emission via localized states and silicon nanoclusters has been studied to get an insight into the excitation and de-excitation processes in silicon-rich oxynitride films. The thermal quenching of Er(3+) luminescence is elucidated by terms of decay time and effective excitation cross section. The temperature quenching of Er(3+) decay time demonstrates the presence of non-radiative trap states, whose density and energy gap between Er(3+) (4) I 13/2 excited levels are reduced by high-temperature annealing. The effective excitation cross section initially increases and eventually decreases with temperature, indicating that the energy transfer process is phonon assisted in both samples.
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Affiliation(s)
- Lingbo Xu
- State Key Laboratory of Silicon Materials and Department of Materials Science and Engineering, Zhejiang University, Hangzhou 310027, People’s Republic of China
| | - Si Li
- State Key Laboratory of Silicon Materials and Department of Materials Science and Engineering, Zhejiang University, Hangzhou 310027, People’s Republic of China
| | - Lu Jin
- State Key Laboratory of Silicon Materials and Department of Materials Science and Engineering, Zhejiang University, Hangzhou 310027, People’s Republic of China
| | - Dongsheng Li
- State Key Laboratory of Silicon Materials and Department of Materials Science and Engineering, Zhejiang University, Hangzhou 310027, People’s Republic of China
| | - Deren Yang
- State Key Laboratory of Silicon Materials and Department of Materials Science and Engineering, Zhejiang University, Hangzhou 310027, People’s Republic of China
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Xu L, Li D, Jin L, Xiang L, Wang F, Yang D, Que D. Evolution of the sensitized Er(3+) emission by silicon nanoclusters and luminescence centers in silicon-rich silica. NANOSCALE RESEARCH LETTERS 2014; 9:456. [PMID: 25258597 PMCID: PMC4164316 DOI: 10.1186/1556-276x-9-456] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/18/2014] [Accepted: 08/27/2014] [Indexed: 06/03/2023]
Abstract
The structural and optical properties of erbium-doped silicon-rich silica samples containing different Si concentrations are studied. Intense photoluminescence (PL) from luminescence centers (LCs) and silicon nanoclusters (Si NCs), which evolves with annealing temperatures, is obtained. By modulating the silicon concentrations in samples, the main sensitizers of Er(3+) ions can be tuned from Si NCs to LCs. Optimum Er(3+) PL, with an enhancement of more than two, is obtained in the samples with a medium Si concentration, where the sensitization from Si NCs and LCs coexists.
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Affiliation(s)
- Lingbo Xu
- State Key Laboratory of Silicon Materials and Department of Materials Science and Engineering, Zhejiang University, Hangzhou, 310027, People’s Republic of China
| | - Dongsheng Li
- State Key Laboratory of Silicon Materials and Department of Materials Science and Engineering, Zhejiang University, Hangzhou, 310027, People’s Republic of China
| | - Lu Jin
- State Key Laboratory of Silicon Materials and Department of Materials Science and Engineering, Zhejiang University, Hangzhou, 310027, People’s Republic of China
| | - Luelue Xiang
- State Key Laboratory of Silicon Materials and Department of Materials Science and Engineering, Zhejiang University, Hangzhou, 310027, People’s Republic of China
| | - Feng Wang
- State Key Laboratory of Silicon Materials and Department of Materials Science and Engineering, Zhejiang University, Hangzhou, 310027, People’s Republic of China
| | - Deren Yang
- State Key Laboratory of Silicon Materials and Department of Materials Science and Engineering, Zhejiang University, Hangzhou, 310027, People’s Republic of China
| | - Duanlin Que
- State Key Laboratory of Silicon Materials and Department of Materials Science and Engineering, Zhejiang University, Hangzhou, 310027, People’s Republic of China
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Photonic effects on the Förster resonance energy transfer efficiency. Nat Commun 2014; 5:3610. [DOI: 10.1038/ncomms4610] [Citation(s) in RCA: 99] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2014] [Accepted: 03/10/2014] [Indexed: 11/08/2022] Open
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