Modifying the composition of hydrogen-terminated silicon nanoparticles synthesized in a nonthermal rf plasma

We have synthesised silicon nanoparticles (Si-NPs) with photoluminescence ranging from blue to IR spectral region using a low-pressure RF plasma in a flow-through glass tube reactor. The spectral position of photoluminescence band of Si-NPs is controlled by the synthesis parameters such as plasma power, silane and hydrogen concentration and pressure in the working area. Modification of Si-NPs surface both on air after the synthesis and in the vacuum chamber by second plasma in methylsilane atmosphere causes a blue spectral shift of the photoluminescence band.

Download Full-text

Neural network modelling of the inductively coupled RF plasma synthesis of silicon nanoparticles

Powder Technology ◽

10.1016/j.powtec.2007.10.004 ◽

2008 ◽

Vol 185 (2) ◽

pp. 109-115 ◽

Cited By ~ 15

Author(s):

Marc Leparoux ◽

Marcel Loher ◽

Cornelis Schreuders ◽

Stephan Siegmann

Keyword(s):

Neural Network ◽

Silicon Nanoparticles ◽

Rf Plasma ◽

Plasma Synthesis ◽

Network Modelling ◽

Inductively Coupled ◽

Neural Network Modelling

Download Full-text

Silicon Nanoparticle Synthesis Using Constricted Mode Capacitive Silane Plasma

MRS Proceedings ◽

10.1557/proc-818-m14.4.1 ◽

2004 ◽

Vol 818 ◽

Cited By ~ 2

Author(s):

A. Bapat ◽

Ying Dong ◽

C. R. Perrey ◽

C. B. Carter ◽

S.A. Campbell ◽

...

Keyword(s):

Inductively Coupled Plasma ◽

Silicon Nanoparticles ◽

Crystalline Silicon ◽

Experimental Studies ◽

Particle Diameter ◽

Single Crystal Silicon ◽

Geometric Standard Deviation ◽

Rf Plasma ◽

Particle Nucleation ◽

Crystal Silicon

AbstractCrystalline semiconductor nanoparticles are of interest for a variety of electronic and opto-electronic applications. We report experimental studies of the synthesis and characterization of crystalline silicon nanoparticles using a constricted-mode capacitive RF plasma in continua- tion of results reported earlier from an RF inductively coupled plasma [1]. The constricted-mode discharge is based on a thermal plasma instability yielding a high-density plasma filament, which rotates at a high frequency. Silane is dissociated, leading to particle nucleation and growth. Particles are extracted by passing the particle-laden gas through an orifice to form a beam and col- lected by inertial impaction.We are able to reproducibly synthesize highly oriented freestanding single-crystal silicon nanoparticles. Monodisperse particle size distributions centered at a 35nm particle diameter with a geometric standard deviation of 1.3 are obtained. Transmission electron microscope (TEM) studies show uniformly shaped cubic particles. Selected-area electron diffraction patterns indi- cate the particles have the diamond-cubic silicon structure. To study the electrical properties of these particles, metal-semiconductor-metal structures were fabricated and analyzed.

Download Full-text

Characterization of homoepitaxial diamond films by Electron microscopy

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100088713 ◽

1991 ◽

Vol 49 ◽

pp. 880-881

Author(s):

D.P. Malta ◽

S.A. Willard ◽

R.A. Rudder ◽

G.C. Hudson ◽

J.B. Posthill ◽

...

Keyword(s):

Electron Microscopy ◽

Surface Defects ◽

Substrate Surface ◽

Diamond Films ◽

Chemical Vapor ◽

Polycrystalline Diamond ◽

Large Degree ◽

Rf Plasma ◽

Semiconducting Diamond

Semiconducting diamond films have the potential for use as a material in which to build active electronic devices capable of operating at high temperatures or in high radiation environments. A major goal of current device-related diamond research is to achieve a high quality epitaxial film on an inexpensive, readily available, non-native substrate. One step in the process of achieving this goal is understanding the nucleation and growth processes of diamond films on diamond substrates. Electron microscopy has already proven invaluable for assessing polycrystalline diamond films grown on nonnative surfaces.The quality of the grown diamond film depends on several factors, one of which is the quality of the diamond substrate. Substrates commercially available today have often been found to have scratched surfaces resulting from the polishing process (Fig. 1a). Electron beam-induced current (EBIC) imaging shows that electrically active sub-surface defects can be present to a large degree (Fig. 1c). Growth of homoepitaxial diamond films by rf plasma-enhanced chemical vapor deposition (PECVD) has been found to planarize the scratched substrate surface (Fig. 1b).

Download Full-text

Interface characterization of nanoscale SiOxlayers grown on RF plasma hydrogenated silicon

Journal of Physics Conference Series ◽

10.1088/1742-6596/700/1/012029 ◽

2016 ◽

Vol 700 ◽

pp. 012029

Author(s):

E Halova ◽

N Kojuharova ◽

S Alexandrova ◽

A Szekeres

Keyword(s):

Rf Plasma ◽

Hydrogenated Silicon ◽

Interface Characterization

Download Full-text

ZnCdO/ZnMgO and ZnO/AlGaN Heterostructures for UV and Visible Light Emitters

MRS Proceedings ◽

10.1557/proc-0892-ff18-01-ee09-01 ◽

2005 ◽

Vol 892 ◽

Cited By ~ 2

Author(s):

Andrei Osinsky ◽

Jianwei Dong ◽

J. Q. Xie ◽

B. Hertog ◽

A. M. Dabiran ◽

...

Keyword(s):

Molecular Beam ◽

Compositional Analysis ◽

Optical Emission ◽

Rf Plasma ◽

Light Emitters ◽

Time Resolved ◽

Light Emitting ◽

Spatially Resolved ◽

Time Resolved Photoluminescence ◽

Made In

AbstractThis paper reviews of some of the progress made in the development of ZnO-based light emitting diodes (LEDs). n-ZnO/p-AlGaN-based heterostructures have been successfully for the fabrication of UV emitting LEDs that have operated at temperatures up to 650K, suggesting an excitonic origin for the optical transitions. RF-plasma-assisted molecular beam epitaxy has been used to grow epitaxial CdxZn1-xO films on GaN/sapphire structure. These films have a single-crystal wurtzite structure as demonstrated by structural and compositional analysis. High quality CdxZn1-xO films were grown with up to x=0.78 mole fraction as determined by RBS and SIMS techniques. Optical emission ranging from purple (Cd0.05Zn0.95O) to yellow (Cd0.29Zn0.71O) was observed. Compositional fluctuations in a Cd0.16Zn0.84O films were not detected by spatially resolved CL measurements, although intensity fluctuation with features of ∼0.5 μm diameter were seen on the intensity maps. Time resolved photoluminescence shows multi-exponential decay with 21 psec. and 49±3 psec. lifetimes, suggesting that composition micro-fluctuations may be present in Cd0.16Zn0.84O film.

Download Full-text

Photocatalytic hydrogen generation using mesoporous silicon nanoparticles: influence of magnesiothermic reduction conditions and nanoparticle aging on the catalytic activity

Nanoscale ◽

10.1039/d0nr07463b ◽

2021 ◽

Vol 13 (4) ◽

pp. 2685-2692

Author(s):

Isabel S. Curtis ◽

Ryan J. Wills ◽

Mita Dasog

Keyword(s):

Catalytic Activity ◽

Hydrogen Production ◽

Silicon Nanoparticles ◽

Hydrogen Generation ◽

Oxide Content ◽

Magnesiothermic Reduction ◽

Mesoporous Silicon ◽

High Crystallinity ◽

Photocatalytic Hydrogen Generation

High crystallinity, low oxide content, and low sintering lead to optimally performing mesoporous Si photocatalysts for solar-driven hydrogen production.

Download Full-text

Silicon nanoparticles elicit an increase in lemongrass (Cymbopogon flexuosus (Steud.) Wats) agronomic parameters with a higher essential oil yield

Journal of Hazardous Materials ◽

10.1016/j.jhazmat.2021.125254 ◽

2021 ◽

Vol 412 ◽

pp. 125254

Author(s):

Mohammad Mukarram ◽

M. Masroor A. Khan ◽

Francisco J. Corpas

Keyword(s):

Essential Oil ◽

Silicon Nanoparticles ◽

Oil Yield ◽

Cymbopogon Flexuosus ◽

Essential Oil Yield

Download Full-text

Optical Constant and Conformality Analysis of SiO2 Thin Films Deposited on Linear Array Microstructure Substrate by PECVD

Coatings ◽

10.3390/coatings11050510 ◽

2021 ◽

Vol 11 (5) ◽

pp. 510

Author(s):

Yongqiang Pan ◽

Huan Liu ◽

Zhuoman Wang ◽

Jinmei Jia ◽

Jijie Zhao

Keyword(s):

Thin Films ◽

Film Thickness ◽

Deposition Rate ◽

Optical Constant ◽

Photoelectron Spectroscopy ◽

Linear Array ◽

Chemical Vapor ◽

Rf Plasma ◽

X Ray ◽

Sio2 Thin Film

SiO2 thin films are deposited by radio frequency (RF) plasma-enhanced chemical vapor deposition (PECVD) technique using SiH4 and N2O as precursor gases. The stoichiometry of SiO2 thin films is determined by the X-ray photoelectron spectroscopy (XPS), and the optical constant n and k are obtained by using variable angle spectroscopic ellipsometer (VASE) in the spectral range 380–1600 nm. The refractive index and extinction coefficient of the deposited SiO2 thin films at 500 nm are 1.464 and 0.0069, respectively. The deposition rate of SiO2 thin films is controlled by changing the reaction pressure. The effects of deposition rate, film thickness, and microstructure size on the conformality of SiO2 thin films are studied. The conformality of SiO2 thin films increases from 0.68 to 0.91, with the increase of deposition rate of the SiO2 thin film from 20.84 to 41.92 nm/min. The conformality of SiO2 thin films decreases with the increase of film thickness, and the higher the step height, the smaller the conformality of SiO2 thin films.

Download Full-text