Growth and Properties of Micro-Crystalline (Si,Ge):H Films

1998 ◽  
Vol 507 ◽  
Author(s):  
Karl Erickson ◽  
Vikram L. Dalal ◽  
George Chumanov
Keyword(s):  
Activation Energy ◽  
Raman Spectroscopy ◽  
Substrate Temperature ◽  
Entire Range ◽  
Plasma Process ◽  
Absorption Data ◽  
Ecr Plasma ◽  
Absorption Constant ◽  
Defect Densities

ABSTRACTThis paper reports on the growth and characterization of micro-crystalline (Si,Ge) films deposited on glass and polyimide substrates. The films were grown using a hydrogen diluted remote ECR plasma process. The feedstock gases were silane and germane. The entire range of composition from 100% Si to 100% Ge was studied. A low-pressure, low-substrate temperature, and high-power environment was used to change the morphology from amorphous to micro-crystalline. The films deposited at 5 mT pressure are generally micro-crystalline. The film's structure was studied using Raman spectroscopy. Raman spectra show clear, sharp crystalline-type Si and Ge peaks. Electronic properties of the films, such as activation energy and absorption constant down to α = 1 cm−1 were also measured. The sub-gap absorption data also show crystalline absorption behavior, with the absorption shifting to lower energies as the Ge content is increased. This absorption data shows that the materials have low defect densities.

scholarly journals Morpho-molecular ex vivo detection and grading of non-muscle-invasive bladder cancer using forward imaging probe based multimodal optical coherence tomography and Raman spectroscopy

The Analyst ◽  
2020 ◽  
Vol 145 (4) ◽  
pp. 1445-1456 ◽  
Author(s):  
Fabian Placzek ◽  
Eliana Cordero Bautista ◽  
Simon Kretschmer ◽  
Lara M. Wurster ◽  
Florian Knorr ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Optical Coherence Tomography ◽  
Imaging System ◽  
Ex Vivo ◽  
Large Field ◽  
Optical Coherence ◽  
Fiber Optic Probe ◽  
Optic Probe ◽  
Muscle Invasive

Characterization of bladder biopsies, using a combined fiber optic probe-based optical coherence tomography and Raman spectroscopy imaging system that allows a large field-of-view imaging and detection and grading of cancerous bladder lesions.

scholarly journals Raman Spectroscopy Investigation of Graphene Oxide Reduction by Laser Scribing

2021 ◽  
Vol 7 (2) ◽  
pp. 48
Author(s):  
Vittorio Scardaci ◽  
Giuseppe Compagnini
Keyword(s):  
Raman Spectroscopy ◽  
Graphene Oxide ◽  
Reduce Graphene Oxide ◽  
Oxide Reduction ◽  
Material Parameters ◽  
Laser Scribing ◽  
Wide Range ◽  
Scan Speed ◽  
Laser Reduction

Laser scribing has been proposed as a fast and easy tool to reduce graphene oxide (GO) for a wide range of applications. Here, we investigate laser reduction of GO under a range of processing and material parameters, such as laser scan speed, number of laser passes, and material coverage. We use Raman spectroscopy for the characterization of the obtained materials. We demonstrate that laser scan speed is the most influential parameter, as a slower scan speed yields poor GO reduction. The number of laser passes is influential where the material coverage is higher, producing a significant improvement of GO reduction on a second pass. Material coverage is the least influential parameter, as it affects GO reduction only under restricted conditions.

Electrical Characterization of Low Temperature GaAs Layers, and Observation of the Extremely Large Carrier Concentrations in Undoped Material

1991 ◽  
Vol 241 ◽  
Author(s):  
Bijan Tadayon ◽  
Mohammad Fatemi ◽  
Saied Tadayon ◽  
F. Moore ◽  
Harry Dietrich
Keyword(s):  
Molecular Beam Epitaxy ◽  
Low Temperature ◽  
Substrate Temperature ◽  
Molecular Beam ◽  
Electrical Characterization ◽  
Physical Characteristics ◽  
Hall Measurements ◽  
Undoped Material ◽  
Low Temperature Gaas

ABSTRACTWe present here the results of a study on the effect of substrate temperature, Ts, on the electrical and physical characteristics of low temperature (LT) molecular beam epitaxy GaAs layers. Hall measurements have been performed on the asgrown samples and on samples annealed at 610 °C and 850 °C. Si implantation into these layers has also been investigated.

FTIR and Raman spectroscopy characterization of functional groups in various rank coals

Fuel ◽  
2017 ◽  
Vol 206 ◽  
pp. 555-563 ◽  
Author(s):  
Xueqiu He ◽  
Xianfeng Liu ◽  
Baisheng Nie ◽  
Dazhao Song
Keyword(s):  
Raman Spectroscopy ◽  
Functional Groups ◽  
Ftir And Raman Spectroscopy

Observation of Rheed Intensity Oscillations During PbSe/CaF2/Si(111) MBE

1996 ◽  
Vol 441 ◽  
Author(s):  
W. K. Liu ◽  
X. M. Fang ◽  
P. J. McCann ◽  
M. B. Santos
Keyword(s):  
Activation Energy ◽  
Melting Point ◽  
Substrate Temperature ◽  
High Melting ◽  
Arrhenius Behavior ◽  
High Activation ◽  
High Melting Point ◽  
Mbe Growth ◽  
Sublimation Energy ◽  
Initial Nucleation

AbstractRHEED intensity oscillations observed during MBE growth of CaF2 on Si(111) and PbSe on CaF2/Si(111) are presented. The effects of substrate temperature and initial nucleation procedure are investigated. Strong temporal oscillations of the specular beam intensity are found to be most readily observed at temperatures below 200°C for both CaF2 and PbSe. Growth rates measured as a function of cell temperatures exhibit Arrhenius behavior with activation energies of 5.0 eV and 1.93 eV for CaF2 and PbSe, respectively. The relatively high activation energy obtained for CaF2 is consistent with the high melting point and sublimation energy of ionic fluorides.

Broadband Coherent Anti-Stokes Raman Spectroscopy Characterization of Polymer Thin Films

2006 ◽  
Vol 60 (10) ◽  
pp. 1097-1102 ◽  
Author(s):  
Zachary D. Schultz ◽  
Marc C. Gurau ◽  
Lee J. Richter
Keyword(s):  
Thin Films ◽  
Raman Spectroscopy ◽  
Polymer Thin Films ◽  
Anti Stokes

scholarly journals Identification of LDPE Grades Focusing on Specific CH2 Raman Vibration Modes

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Richard Jumeau ◽  
Patrice Bourson ◽  
Michel Ferriol ◽  
François Lahure ◽  
Marc Ponçot ◽  
...  
Keyword(s):  
Differential Scanning Calorimetry ◽  
Raman Spectroscopy ◽  
Vibrational Spectroscopy ◽  
Phenomenological Model ◽  
Low Density ◽  
Vibration Modes ◽  
Scanning Calorimetry ◽  
Lamella Thickness ◽  
Poly Ethylene

The possibilities of applications of vibrational spectroscopy techniques (Raman spectroscopy) in the analysis and characterization of polymers are more and more used and accurate. In this paper, our purpose is to characterize Low Density Poly(Ethylene) (LDPE) grades by Raman spectroscopy and in particular with CH2 Raman vibration modes. With temperature measurements, we determine different amorphous and crystalline Raman assignments. From these results and on the basis of the evolution of CH2 bending Raman vibration modes, we develop a phenomenological model in correlation with Differential Scanning Calorimetry and in particular with crystalline lamella thickness determination.

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