scholarly journals Spectral tuning of colloidal Si nanocrystal luminescence by post-laser irradiation in liquid

RSC Advances ◽  
2020 ◽  
Vol 10 (54) ◽  
pp. 32992-32998
Author(s):  
Ze Yuan ◽  
Toshihiro Nakamura
Keyword(s):  
Laser Irradiation ◽  
Silicon Nanocrystals ◽  
Simple Technique ◽  
Luminescence Spectra ◽  
Ultraviolet Region ◽  
Spectral Tuning ◽  
Si Nanocrystal

We report a simple technique to tune the luminescence spectra of blue-emitting colloidal silicon nanocrystals (Si-ncs) to the ultraviolet region via post-laser irradiation.

Creation of locally selective mirror surface on 40BaO–40TiO2–20B2O3 glass by XeCl pulse laser irradiation

2007 ◽  
Vol 22 (5) ◽  
pp. 1270-1274
Author(s):  
Hirokazu Masai ◽  
Shintaro Mizuno ◽  
Takumi Fujiwara ◽  
Yasuhiko Benino ◽  
Takayuki Komatsu ◽  
...  
Keyword(s):  
Absorption Coefficient ◽  
Laser Irradiation ◽  
Flat Surface ◽  
Present Finding ◽  
Mechanical Polishing ◽  
Ultraviolet Region ◽  
Present System ◽  
Xecl Laser ◽  
Pulse Laser Irradiation ◽  
Increasing Temperature

Creation of mirror dots, localized areas of smooth surface with a shape of laser beam on a glass material, using a XeCl laser irradiation is reported. Laser irradiation of a 40BaO–40TiO2–20B2O3 sample heated to 300 °C induced a smooth and flat surface, where no scratches caused by a mechanical polishing were observed. The present finding indicates that the melting of the surface occurred by the combined effect of the heat-assistance and the increased absorption coefficient of TiO2. In the present system, the absorption coefficient in the ultraviolet region, which originates from TiO2, was found to increase with increasing temperature. The presented technique will open new possibilities in integrated optics; the surface of a small protruded or hollow area can be made smooth, which cannot be achieved by conventional mechanical polishing.

Effect of Microcavity Structures on the Photoluminescence of Silicon Nanocrystals

2003 ◽  
Vol 770 ◽  
Author(s):  
Marc G. Spooner ◽  
Timothy M. Walsh ◽  
Robert G. Elliman
Keyword(s):  
Chemical Vapour Deposition ◽  
Silicon Nanocrystals ◽  
Vapour Deposition ◽  
Chemical Vapour ◽  
Optical Emission ◽  
Emission Source ◽  
Oxide Layers ◽  
Si Nanocrystals ◽  
Si Nanocrystal ◽  
Form Part

Abstractptical microcavity structures containing Si nanocrystals are fabricated by plasma enhanced chemical vapour deposition (PECVD) of SiO2, Si3N4 and SiOx layers. The nanocrystals are formed within Si-rich oxide layers (SiOx) by precipitation and growth, and the microcavity structures defined by two parallel distributed Bragg mirrors (DBM) made from either alternate SiO2/Si3N4 layers or alternate SiO2/SiOx layers. In the latter case, Si nanocrystal layers form part of the DBM structure thereby providing a distributed emission source. The optical emission from these and related structures are examined and compared with that from isolated nanocrystal layers.

Optical Fabrication of Semiconductor Single-Crystalline Microspheres in Superfluid Helium

2014 ◽  
Vol 1635 ◽  
pp. 103-108 ◽  
Author(s):  
Shinya Okamoto ◽  
Satoshi Ichikawa ◽  
Yosuke Minowa ◽  
Masaaki Ashida
Keyword(s):  
Superfluid Helium ◽  
Luminescence Spectra ◽  
Ultraviolet Region ◽  
Optical Fabrication ◽  
Strong Light ◽  
Time Resolved ◽  
Light Matter Interaction ◽  
Time Resolved Photoluminescence ◽  
Spherical Microparticles ◽  
Typical Mode

ABSTRACTWe successfully fabricated semiconductor microspheres of ZnO, ZnSe, etc., by laser ablation in superfluid helium and investigated their morphology and optical properties. Time-resolved photoluminescence spectroscopy in ultraviolet region of single ZnO microspheres shows luminescence spectra with mode structures and remarkable reduction of the luminescence decay time compared to that of polycrystals or non-spherical microparticles. This indicates strong light-matter interaction due to efficient light-confinement in the ZnO microspheres. In addition, the fabricated ZnSe microspheres also show the photoluminescence spectra with typical mode structures indicating their high sphericity.

Fine Structures in Luminescence Spectra of NaNO2 Crystal in the Ultraviolet Region

1977 ◽  
Vol 42 (5) ◽  
pp. 1660-1668 ◽  
Author(s):  
Masao Kamada ◽  
Tetsuzo Yoshimura ◽  
Riso Kato
Keyword(s):  
Luminescence Spectra ◽  
Ultraviolet Region ◽  
Fine Structures

Luminescence and Microstructure of Microspheres Containing Silicon Nanocrystals

2003 ◽  
Vol 777 ◽  
Author(s):  
C.A. Ryan ◽  
A. Meldrum ◽  
C.W. White
Keyword(s):  
Silicon Nanocrystals ◽  
Near Infrared ◽  
Light Emission ◽  
Resonant Cavity ◽  
Fused Silica ◽  
Luminescence Spectra ◽  
Visible Range ◽  
Cavity Modes ◽  
Potential Applications ◽  
Silicon Implantation

AbstractThe strong visible photoluminescence (PL) of silicon nanocrystals has recently been the focus of considerable research interest. Nanocrystal composites produced by silicon implantation of a fused silica wafer followed by high-temperature thermal processing are characterized by a strong, broad photoluminescence spectrum. This light emission, centered in the near infrared and extending well into the visible range, has potential applications for the development of photonic materials based on silicon nanostructures. Here, we report on our attempts to form luminescent silica microspheres containing embedded silicon nanocrystals. Arrays of luminescent microspheres were successfully fabricated, without significant coagulation or destruction of the silica spheres during the silicon ion implantation step. However, a substantial deformation on the surface of the spheres that occurred during the high-flux implantation prevented the development of resonant cavity modes in the luminescence spectra. Resonant modes could clearly be observed for pre-implanted and annealed SiO2 wafers with a layer of pristine microspheres subsequently deposited on the implanted surface. These results suggest an alternative method for producing highly durable luminescent silica “microbeads”. At lower ion fluxes, the development of luminescent microsphere superlattices with novel optical properties due to coupling of the light emission from the silicon nanocrystals into the resonant cavity modes may be possible if the deformation effects can be reduced or eliminated.

scholarly journals Emission spectra of noble gases and their mixtures under ion beam excitation

2016 ◽  
Vol 34 (4) ◽  
pp. 655-662 ◽  
Author(s):  
M.U. Khasenov
Keyword(s):  
Atomic Oxygen ◽  
Noble Gases ◽  
Ion Beam ◽  
Emission Spectra ◽  
Heavy Ion ◽  
Luminescence Spectra ◽  
Ultraviolet Region ◽  
Oh Radical ◽  
Excimer Molecule ◽  
Beam Excitation

AbstractThe luminescence spectra of noble gases and their binary mixtures were measured using heavy ion beam excitation from a DC-60 accelerator. Spectra were measured in the range of 200–975 nm; the gas spectra were dominated by lines ofp–sandd–patomic transitions; in neon and argon, lines from atomic oxygen, N2, N2+, and OH radical bands were also observed. The ultraviolet region of the spectra was represented by a “third continuum” of noble gases. In krypton, the band of the KrO excimer molecule with a maximum at 557 nm was also observed. The maxima of the heteronuclear ionic molecules bands were located at wavelengths of 329 and 506 nm (Ar–Xe), 491 nm (Kr–Xe), and 642 nm (Ar–Kr). The relative intensities of the 2p–1stransitions of the noble gases atoms were measured and are discussed.

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