High-temperature nitrogen annealing induced bonding states and photoluminescence changes in inductively coupled plasma torch synthesized silicon nanostructures

2020 ◽  
Vol 128 (2) ◽  
pp. 024302 ◽  
Author(s):  
Sonia Freddi ◽  
Filippo Fabbri ◽  
Annalisa Cannizzaro ◽  
Marta Agati ◽  
Richard Dolbec ◽  
...  
Keyword(s):  
High Temperature ◽  
Inductively Coupled Plasma ◽  
Plasma Torch ◽  
Silicon Nanostructures ◽  
Inductively Coupled ◽  
Nitrogen Annealing

scholarly journals Power Dissipation of an Inductively Coupled Plasma Torch under E Mode Dominated Regime

Micromachines ◽  
2021 ◽  
Vol 12 (7) ◽  
pp. 834
Author(s):  
Nan Yu ◽  
Renaud Jourdain ◽  
Mustapha Gourma ◽  
Fangda Xu ◽  
Adam Bennett ◽  
...  
Keyword(s):  
Power Dissipation ◽  
Inductively Coupled Plasma ◽  
Plasma Torch ◽  
Electrical Response ◽  
Inductively Coupled ◽  
De Laval Nozzle ◽  
Surface Fabrication ◽  
Icp Torch ◽  
Frequency Power

This paper focuses on the power dissipation of a plasma torch used for an optical surface fabrication process. The process utilizes an inductively coupled plasma (ICP) torch that is equipped with a De-Laval nozzle for the delivery of a highly collimated plasma jet. The plasma torch makes use of a self-igniting coil and an intermediate co-axial tube made of alumina. The torch has a distinctive thermal and electrical response compared to regular ICP torches. In this study, the results of the power dissipation investigation reveal the true efficiency of the torch and discern its electrical response. By systematically measuring the coolant parameters (temperature change and flow rate), the power dissipation is extrapolated. The radio frequency power supply is set to 800 W, E mode, throughout the research presented in this study. The analytical results of power dissipation, derived from the experiments, show that 15.4% and 33.3% are dissipated by the nozzle and coil coolant channels, respectively. The experiments also enable the determination of the thermal time constant of the plasma torch for the entire range of RF power.

scholarly journals Crystal Chemistry and Luminescence Properties of Eu-Doped Polycrystalline Hydroxyapatite Synthesized by Chemical Precipitation at Room Temperature

Crystals ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 250 ◽  
Author(s):  
Francesco Baldassarre ◽  
Angela Altomare ◽  
Nicola Corriero ◽  
Ernesto Mesto ◽  
Maria Lacalamita ◽  
...  
Keyword(s):  
Fourier Transform ◽  
High Temperature ◽  
Inductively Coupled Plasma ◽  
Room Temperature ◽  
Annealing Temperature ◽  
Chemical Precipitation ◽  
Precipitation Method ◽  
X Ray Diffraction ◽  
X Ray ◽  
Inductively Coupled

Europium-doped hydroxyapatite Ca10(PO4)6(OH)2 (3% mol) powders were synthesized by an optimized chemical precipitation method at 25 °C, followed by drying at 120 °C and calcination at 450 °C and 900 °C. The obtained nanosized crystallite samples were investigated by means of a combination of inductively coupled plasma (ICP) spectroscopy, powder X-ray diffraction (PXRD), Fourier Transform Infrared (FTIR), Raman and photoluminescence (PL) spectroscopies. The Rietveld refinement in the hexagonal P63/m space group showed europium ordered at the Ca2 site at high temperature (900 °C), and at the Ca1 site for lower temperatures (120 °C and 450 °C). FTIR and Raman spectra showed slight band shifts and minor modifications of the (PO4) bands with increasing annealing temperature. PL spectra and decay curves revealed significant luminescence emission for the phase obtained at 900 °C and highlighted the migration of Eu from the Ca1 to Ca2 site as a result of increasing calcinating temperature.

scholarly journals Ultrafast Carrier Relaxation Dynamics in Quantum Confined Non-Isotropic Silicon Nanostructures Synthesized by an Inductively Coupled Plasma Process

Materials ◽  
2020 ◽  
Vol 13 (19) ◽  
pp. 4267
Author(s):  
Stefano Ponzoni ◽  
Sonia Freddi ◽  
Marta Agati ◽  
Vincent Le Borgne ◽  
Simona Boninelli ◽  
...  
Keyword(s):  
Photon Energy ◽  
Silicon Nanowires ◽  
Inductively Coupled Plasma ◽  
Inner Core ◽  
Optical Measurements ◽  
Spectral Energy ◽  
Silicon Nanostructures ◽  
Relaxation Dynamics ◽  
Plasma Process ◽  
Inductively Coupled

To exploit the optoelectronic properties of silicon nanostructures (SiNS) in real devices, it is fundamental to study the ultrafast processes involving the photogenerated charges separation, migration and lifetime after the optical excitation. Ultrafast time-resolved optical measurements provide such information. In the present paper, we report on the relaxation dynamics of photogenerated charge-carriers in ultrafine SiNS synthesized by means of inductively-coupled-plasma process. The carriers’ transient regime was characterized in high fluence regime by using a tunable pump photon energy and a broadband probe pulse with a photon energy ranging from 1.2 eV to 2.8 eV while varying the energy of the pump photons and their polarization. The SiNS consist of Si nanospheres and nanowires (NW) with a crystalline core embedded in a SiOx outer-shell. The NW inner core presents different typologies: long silicon nanowires (SiNW) characterized by a continuous core (with diameters between 2 nm and 15 nm and up to a few microns long), NW with disconnected fragments of SiNW (each fragment with a length down to a few nanometers), NW with a “chaplet-like” core and NW with core consisting of disconnected spherical Si nanocrystals. Most of these SiNS are asymmetric in shape. Our results reveal a photoabsorption (PA) channel for pump and probe parallel polarizations with a maximum around 2.6 eV, which can be associated to non-isotropic ultra-small SiNS and ascribed either to (i) electron absorption driven by the probe from some intermediate mid-gap states toward some empty state above the bottom of the conduction band or (ii) the Drude-like free-carrier presence induced by the direct-gap transition in the their band structure. Moreover, we pointed up the existence of a broadband and long-living photobleaching (PB) in the 1.2–2.0 eV energy range with a maximum intensity around 1.35 eV which could be associated to some oxygen related defect states present at the Si/SiOx interface. On the other hand, this wide spectral energy PB can be also due to both silicon oxide band-tail recombination and small Si nanostructure excitonic transition.

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