1
|
Raman amplification for trapped radiation in crystalline single Si nanoparticle. Sci Rep 2023; 13:1014. [PMID: 36653377 PMCID: PMC9849211 DOI: 10.1038/s41598-023-27839-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2022] [Accepted: 01/09/2023] [Indexed: 01/20/2023] Open
Abstract
In a single crystalline Si particle, we observed a huge amplification of the Raman peak at 521 cm-1. With an AFM microscope, coupled with a Micro-Raman spectrometer, we investigate a single Si particle at wavelengths of 532 nm, 633 nm, and 785 nm. As observed by transmission electron microscopy, it has an octahedral shape of 150 nm in size. Thermal effects were detected on the Raman peak when the laser radiation, trapped inside, determines the heating of the particle up to its fusion. In these cases, the Raman peak splits into two components, the first at the crystal position and the other shifted at a lower value. The data permit the identification of the amplification mechanism of the Raman peak as trapped radiation moving forward and backwards into the particle. The thermal effects are attributed to phonon confinement and reduced thermal exchange with the surrounding. The present results are discussed in light of local order, the uncertainty principle, and phonon dispersion curves, and corroborated by shape-dependent simulation of absorption, scattering, and extinction behaviour.
Collapse
|
2
|
de Jong EMLD, Rutjes H, Valenta J, Trinh MT, Poddubny AN, Yassievich IN, Capretti A, Gregorkiewicz T. Thermally stimulated exciton emission in Si nanocrystals. LIGHT, SCIENCE & APPLICATIONS 2018; 7:17133. [PMID: 30839625 PMCID: PMC6107050 DOI: 10.1038/lsa.2017.133] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/27/2017] [Revised: 09/14/2017] [Accepted: 09/15/2017] [Indexed: 06/09/2023]
Abstract
Increasing temperature is known to quench the excitonic emission of bulk silicon, which is due to thermally induced dissociation of excitons. Here, we demonstrate that the effect of temperature on the excitonic emission is reversed for quantum-confined silicon nanocrystals. Using laser-induced heating of silicon nanocrystals embedded in SiO2, we achieved a more than threefold (>300%) increase in the radiative (photon) emission rate. We theoretically modeled the observed enhancement in terms of the thermally stimulated effect, taking into account the massive phonon production under intense illumination. These results elucidate one more important advantage of silicon nanostructures, illustrating that their optical properties can be influenced by temperature. They also provide an important insight into the mechanisms of energy conversion and dissipation in ensembles of silicon nanocrystals in solid matrices. In practice, the radiative rate enhancement under strong continuous wave optical pumping is relevant for the possible application of silicon nanocrystals for spectral conversion layers in concentrator photovoltaics.
Collapse
Affiliation(s)
- Elinore MLD de Jong
- Van der Waals-Zeeman Institute, University of Amsterdam, Science Park 904, 1098 XH, Amsterdam, The Netherlands
| | - Huub Rutjes
- Van der Waals-Zeeman Institute, University of Amsterdam, Science Park 904, 1098 XH, Amsterdam, The Netherlands
| | - Jan Valenta
- Department of Chemical Physics and Optics, Faculty of Mathematics and Physics, Charles University, Ke Karlovu 3, 121 16 Prague 2, Czech Republic
| | - M Tuan Trinh
- Department of Electrical Engineering and Computer Science, University of Michigan, 2200 Bonisteel Blvd, Ann Arbor, MI 48109, USA
| | - Alexander N Poddubny
- Ioffe Institute, Russian Academy of Sciences, 26 Polytechnicheskaya, 194021 St Petersburg, Russia
| | - Irina N Yassievich
- Ioffe Institute, Russian Academy of Sciences, 26 Polytechnicheskaya, 194021 St Petersburg, Russia
| | - Antonio Capretti
- Van der Waals-Zeeman Institute, University of Amsterdam, Science Park 904, 1098 XH, Amsterdam, The Netherlands
| | - Tom Gregorkiewicz
- Van der Waals-Zeeman Institute, University of Amsterdam, Science Park 904, 1098 XH, Amsterdam, The Netherlands
| |
Collapse
|
3
|
Zhou HP, Xu M, Xu S, Liu LL, Liu CX, Kwek LC, Xu LX. Hydrogen-plasma-induced Rapid, Low-Temperature Crystallization of μm-thick a-Si:H Films. Sci Rep 2016; 6:32716. [PMID: 27600866 PMCID: PMC5013535 DOI: 10.1038/srep32716] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2016] [Accepted: 08/11/2016] [Indexed: 11/18/2022] Open
Abstract
Being a low-cost, mass-production-compatible route to attain crystalline silicon, post-deposition crystallization of amorphous silicon has received intensive research interest. Here we report a low-temperature (300 °C), rapid (crystallization rate of ~17 nm/min) means of a-Si:H crystallization based on high-density hydrogen plasma. A model integrating the three processes of hydrogen insertion, etching, and diffusion, which jointly determined the hydrogenation depth of the excess hydrogen into the treated micrometer thick a-Si:H, is proposed to elucidate the hydrogenation depth evolution and the crystallization mechanism. The effective temperature deduced from the hydrogen diffusion coefficient is far beyond the substrate temperature of 300 °C, which implies additional driving forces for crystallization, i.e., the chemical annealing/plasma heating and the high plasma sheath electric field. The features of LFICP (low-frequency inductively coupled plasma) and LFICP-grown a-Si:H are also briefly discussed to reveal the underlying mechanism of rapid crystallization at low temperatures.
Collapse
Affiliation(s)
- H P Zhou
- School of Energy Science and Engineering, University of Electronic Science and Technology of China, 2006 Xiyuan Ave, West High-Tech Zone, Chengdu, 611731, China.,Plasma Sources and Application Center, NIE, and Institute of Advanced Studies, Nanyang Technological University, 637616, Singapore
| | - M Xu
- Key Laboratory of Information Materials of Sichuan Province &School of Electrical and Information Engineering, Southwest University for Nationalities, Chengdu 610041, China
| | - S Xu
- Plasma Sources and Application Center, NIE, and Institute of Advanced Studies, Nanyang Technological University, 637616, Singapore
| | - L L Liu
- Institute of Microstructure and Properties of Advanced Materials, Beijing University of Technology, Beijing, 100124, China
| | - C X Liu
- Institute of Microstructure and Properties of Advanced Materials, Beijing University of Technology, Beijing, 100124, China
| | - L C Kwek
- Centre for Quantum Technologies, National University of Singapore, 119077, Singapore
| | - L X Xu
- Plasma Sources and Application Center, NIE, and Institute of Advanced Studies, Nanyang Technological University, 637616, Singapore
| |
Collapse
|
4
|
Strong infrared photoluminescence in highly porous layers of large faceted Si crystalline nanoparticles. Sci Rep 2016; 6:25664. [PMID: 27216452 PMCID: PMC4877587 DOI: 10.1038/srep25664] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2015] [Accepted: 04/11/2016] [Indexed: 11/17/2022] Open
Abstract
Almost all physical processes in solids are influenced by phonons, but their effect is frequently overlooked. In this paper, we investigate the photoluminescence of large silicon nanoparticles (approximately 100 nm size, synthesized by chemical vapor deposition) in the visible to the infrared detection range. We find that upon increasing laser irradiance, an enormous photoluminescence emission band appears in the infrared. Its intensity exhibits a superlinear power dependence, increasing over four orders of magnitude in the investigated pump power range. Particles of different sizes as well as different shapes in porous layers are investigated. The results are discussed taking into account the efficient generation of phonons under high-power pumping, and the reduced capability, porosity dependent, of the silicon nanoparticles to exchange energy with each other and with the substrate. Our findings are relevant for heat management strategies in silicon.
Collapse
|
5
|
Mannino G, Alberti A, Ruggeri R, Libertino S, Pennisi AR, Faraci G. Octahedral faceted Si nanoparticles as optical traps with enormous yield amplification. Sci Rep 2015; 5:8354. [PMID: 25667059 PMCID: PMC5389026 DOI: 10.1038/srep08354] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2014] [Accepted: 01/16/2015] [Indexed: 11/23/2022] Open
Abstract
We describe a method for the creation of an efficient optical scatter trap by using fully crystalline octahedral Silicon nanoparticles (Si-NPs) of approximately 100 nanometres in size. The light trapping, even when probing an isolated nanoparticle, is revealed by an enormous amplification of the Raman yield of up to 108 times that of a similar Si bulk volume. The mechanism conceived and optimised for obtaining such a result was related to the capability of a Si octahedron to trap the light because of its geometrical parameters. Furthermore, Si-NPs act as very efficient light scatterers not only for the direct light beam but also for the trapped light after it escapes the nanoparticle. These two effects are observed, either superimposed or separated, by means of the Raman yield and by photoluminescence enhancements. The inductively coupled plasma synthesis process performed at a temperature of only 50°C allows for the ubiquitous use of these particles on several substrates for optical and photovoltaic applications.
Collapse
Affiliation(s)
| | | | - Rosa Ruggeri
- CNR-IMM, Strada VIII n°5, 95121 Catania, (Italy)
| | | | - Agata R Pennisi
- Università di Catania, Dipartimento di Fisica e Astronomia, Via Santa Sofia 64, 95123 Catania, (Italy)
| | - Giuseppe Faraci
- Università di Catania, Dipartimento di Fisica e Astronomia, Via Santa Sofia 64, 95123 Catania, (Italy)
| |
Collapse
|