Room-Temperature Measurement of Photoluminescence Spectra of Semiconductors Using an FT-Raman Spectrophotometer

1993 ◽  
Vol 47 (11) ◽  
pp. 1814-1819 ◽  
Author(s):  
J. D. Webb ◽  
D. J. Dunlavy ◽  
T. Ciszek ◽  
R. K. Ahrenkiel ◽  
M. W. Wanlass ◽  
...  
Keyword(s):  
Room Temperature ◽  
Optical Devices ◽  
Stray Light ◽  
Gallium Indium Arsenide ◽  
Photoluminescence Spectra ◽  
Bulk Silicon ◽  
Copper Indium ◽  
Germanium Alloy ◽  
Ft Ir ◽  
Ft Raman

This paper demonstrates the utility of an FT-Raman accessory for an FT-IR spectrophotometer in obtaining the room-temperature photoluminescence (PL) spectra of semiconductors used in photovoltaic and electro-optical devices. Sample types analyzed by FT-IR/PL spectroscopy included bulk silicon and films of gallium indium arsenide phosphide (GaInAsP), copper indium diselenide (CuInSe2), and gallium arsenide-germanium alloy on various substrates. The FT-IR/PL technique exhibits advantages in speed, sensitivity, and freedom from stray light over conventional dispersive methods, and can be used in some cases to characterize complete semiconductor devices as well as component materials at room temperature. Some suggestions for improving the spectral range of the technique and removing instrumental spectral artifacts are presented.

Room Temperature Measurement of Photoluminescence Spectra of Semiconductors Using an Ft-Raman Spectrophotometer

1993 ◽  
Vol 324 ◽  
Author(s):  
J. D. Webb ◽  
D. J. Dunlavy ◽  
T. Ciszek ◽  
R. K. Ahrenkiel ◽  
M. W. Wanlass ◽  
...  
Keyword(s):  
Indium Arsenide ◽  
Room Temperature ◽  
Optical Devices ◽  
Stray Light ◽  
Gallium Indium Arsenide ◽  
Photoluminescence Spectra ◽  
Bulk Silicon ◽  
Copper Indium ◽  
Germanium Alloy ◽  
Ft Raman

AbstractThis paper demonstrates the utility of a Fourier transform (FT) Raman spectrophotometer in obtaining the room-temperature photoluminescence (PL) spectra of semiconductors used in photovoltaic and electro-optical devices. Sample types analyzed by FT-PL spectroscopy included bulk silicon and films of copper indium diselenide (CuInSej), gallium indium arsenide (GaInAs), indium phosphide arsenide, (InPAs), and gallium arsenide-germanium alloy (GaAsGe) on various substrates. The FTIR-PL technique exhibits advantages in speed, sensitivity, and freedom from stray light over conventional dispersive methods, and can be used in some cases to characterize complete semiconductor devices as well as component materials at room temperature. Recent innovations that improve the spectral range of the technique and eliminate instrumental spectral artifacts are described.

scholarly journals Prominent luminescence of silicon-vacancy defects created in bulk silicon carbide p–n junction diodes

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Fumiya Nagasawa ◽  
Makoto Takamura ◽  
Hiroshi Sekiguchi ◽  
Yoshinori Miyamae ◽  
Yoshiaki Oku ◽  
...  
Keyword(s):  
Silicon Carbide ◽  
Room Temperature ◽  
Photoluminescence Spectra ◽  
Bulk Silicon ◽  
Electron Dose ◽  
Vacancy Defects ◽  
Silicon Vacancy ◽  
Temperature Electron ◽  
Electroluminescence Intensity ◽  
Bulk Substrate

AbstractWe investigate fluorescent defect centers in 4H silicon carbide p–n junction diodes fabricated via aluminum-ion implantation into an n-type bulk substrate without the use of an epitaxial growth process. At room temperature, electron-irradiated p–n junction diodes exhibit electroluminescence originating from silicon-vacancy defects. For a diode exposed to an electron dose of $$1 \times 10^{18}\,{{\mathrm{cm}}}^{-2}$$ 1 × 10 18 cm - 2 at $$800\,{{\mathrm{keV}}}$$ 800 keV , the electroluminescence intensity of these defects is most prominent within a wavelength range of 400–$$1100\,{{\mathrm{nm}}}$$ 1100 nm . The commonly observed $${{\mathrm{D}}}_1$$ D 1 emission was sufficiently suppressed in the electroluminescence spectra of all the fabricated diodes, while it was detected in the photoluminescence measurements. The photoluminescence spectra also displayed emission lines from silicon-vacancy defects.

Theophylline Cocrystallized with Salicylic Acid and Picolinic Acid: Preparation and Physical Properties

2013 ◽  
Vol 699 ◽  
pp. 682-688 ◽  
Author(s):  
Somphon Weenawan ◽  
Sopita Khumponkrung ◽  
Kenneth J. Haller
Keyword(s):  
Salicylic Acid ◽  
Respiratory Diseases ◽  
Room Temperature ◽  
Slow Release ◽  
Picolinic Acid ◽  
Physical Stability ◽  
Aqueous Solubility ◽  
Ph Control ◽  
Ft Ir ◽  
Ft Raman

Theophylline (TP) is an oral bronchodilator medicine, used to treat respiratory diseases. The problem of TP is low aqueous solubility, slow release tablets, and solid state interconversion between anhydrous and monohydrate forms as a function of relative humidity (RH). Physicochemical properties of this medicine, including solubility, humidity sensitivity, and chemical and physical stability can be improved by cocrystallizing with another compound. Herein we present the cocrystallization of TP with salicylic acid (SA) and picolinic acid (PI). Mixtures of 2:1 TP-SA and TP-PI were screened by solvent-drop grinding, crystal growth by slow evaporation and pH control at 2.0 and 7.0, and compared to the 1:1 crystalline products of TP-SA and TP-PI. The products were characterized by XRD, FT-IR/FT-Raman, and DSC/TG. Crystals of the 1:1 TP-SA, 1:1 TP-PI, and pure TP were stored at room temperature (342 °C) with 582% RH for one month and their stability examined by FT-IR.

Mechanical Properties and Dislocation Structure of Single Crystal Cdte Deformed in Compression at 300°C

1976 ◽  
Vol 34 ◽  
pp. 592-593
Author(s):  
Ernest L. Hall ◽  
J. B. Vander Sande
Keyword(s):  
Mechanical Properties ◽  
Single Crystal ◽  
Dislocation Structure ◽  
Room Temperature ◽  
Elevated Temperatures ◽  
Strain Curve ◽  
Optical Devices ◽  
Semiconductor Compound ◽  
Wide Range ◽  
Sample Orientation

The present paper describes research on the mechanical properties and related dislocation structure of CdTe, a II-VI semiconductor compound with a wide range of uses in electrical and optical devices. At room temperature CdTe exhibits little plasticity and at the same time relatively low strength and hardness. The mechanical behavior of CdTe was examined at elevated temperatures with the goal of understanding plastic flow in this material and eventually improving the room temperature properties. Several samples of single crystal CdTe of identical size and crystallographic orientation were deformed in compression at 300°C to various levels of total strain. A resolved shear stress vs. compressive glide strain curve (Figure la) was derived from the results of the tests and the knowledge of the sample orientation.

Density functional theory, Comparative vibrational spectroscopic studies, HOMO-LUMO, and NBO analysis of Trichloro isocyanuric acid and Trithio cyanuric acid

2015 ◽  
Vol 8 (3) ◽  
pp. 2197-2221
Author(s):  
Theraviyum Chithambarathanu ◽  
M. Darathi ◽  
J. DaisyMagdaline ◽  
S. Gunasekaran
Keyword(s):  
Density Functional ◽  
Cyanuric Acid ◽  
Nbo Analysis ◽  
Basis Set ◽  
Potential Energy Distribution ◽  
Point Energy ◽  
Isocyanuric Acid ◽  
Ft Ir ◽  
Homo Lumo ◽  
Ft Raman

The molecular vibrations of Trichloro isocyanuric acid (C3Cl3N3O3) and Trithio cyanuric acid (C3H3N3S3) have been investigated in polycrystalline sample at room temperature by Fourier Transform Infrared (FT-IR) and FT-Raman spectroscopies in the region 4000-450 cm-1 and 4000-50 cm-1 respectively, which provide a wealth of structural information about the molecules. The spectra are interpreted with the aid of normal co-ordinate analysis following full structure optimization and force field calculations based on density functional theory   (DFT) using standard B3LYP / 6-311++ G (d, p) basis set for investigating the structural and spectroscopic properties. The vibrational frequencies are calculated and the scaled values are compared with experimental FT-IR and FT-Raman spectra. The scaled theoretical wave numbers shows very good agreement with experimental ones. The complete vibrational assignments are performed on the basis of potential energy distribution (PED) of vibrational modes, calculated with scaled quantum (SQM) method. Stability of the molecule arising from hyper conjugative interactions, charge delocalization has been analyzed using natural bond orbital (NBO) analysis. The results show that change in electron density (ED) in σ* and π* anti-bonding orbitals and second order delocalization   energy (E2) confirm the occurrence of Intra molecular Charge Transfer (ICT) within the molecule. The thermodynamic properties like heat capacity, entropy, enthalpy and zero point energy have been calculated for the molecule. The frontier molecular orbitals have been visualized and the HOMO-LUMO energy gap has been calculated. The Molecular Electrostatic Potential (MEP) analysis reveals the sites for electrophilic attack and nucleophilic reactions in the molecule.

scholarly journals Structural and Enhanced Optical Properties of Stabilized γ‒Bi2O3 Nanoparticles: Effect of Oxygen Ion Vacancies

Nanomaterials ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 1023 ◽  
Author(s):  
Ashish Chhaganlal Gandhi ◽  
Chia-Liang Cheng ◽  
Sheng Yun Wu
Keyword(s):  
Room Temperature ◽  
Excess Oxygen ◽  
Ambient Atmosphere ◽  
Photoluminescence Spectra ◽  
X Ray Diffraction ◽  
X Ray ◽  
Band Emission ◽  
Oxygen Ion ◽  
Integrated Intensity ◽  
Effect Of Oxygen

We report the synthesis of room temperature (RT) stabilized γ–Bi2O3 nanoparticles (NPs) at the expense of metallic Bi NPs through annealing in an ambient atmosphere. RT stability of the metastable γ–Bi2O3 NPs is confirmed using synchrotron radiation powder X-ray diffraction and Raman spectroscopy. γ–Bi2O3 NPs exhibited a strong red-band emission peaking at ~701 nm, covering 81% integrated intensity of photoluminescence spectra. Our findings suggest that the RT stabilization and enhanced red-band emission of γ‒Bi2O3 is mediated by excess oxygen ion vacancies generated at the octahedral O(2) sites during the annealing process.

scholarly journals Clean one-pot multicomponent synthesis of pyrans using a green and magnetically recyclable heterogeneous nanocatalyst

SynOpen ◽  
2021 ◽  
Author(s):  
Mina Ghassemi ◽  
Ali Maleki
Keyword(s):  
Room Temperature ◽  
Significant Loss ◽  
Copper Ferrite ◽  
Multicomponent Synthesis ◽  
Thermo Gravimetric ◽  
Sem Images ◽  
One Pot ◽  
Three Component Reaction ◽  
Ft Ir ◽  
The One

Copper ferrite (CuFe2O4) magnetic nanoparticles (MNPs) were synthesized via thermal decomposition method and applied as a reusable and green catalyst in the synthesis of functionalized 4H-pyran derivatives using malononitrile, an aromatic aldehyde and a β-ketoester in ethanol at room temperature. Then it was characterized by Fourier transform infrared spectroscopy (FT-IR), energy-dispersive X-ray spectroscopy (EDX) analysis, scanning electron microscopy (SEM) images, thermo gravimetric and differential thermo gravimetric (TGA/DTG) analysis. The catalyst was recovered from the reaction mixture by applying an external magnet and decanting the mixture. Recycled catalyst was reused for several times without significant loss in its activity. Running the one-pot three-component reaction at room temperature, no use of eternal energy source and using a green solvent provide benign, mild, and environmentally friendly reaction conditions; as well, ease of catalyst recovering, catalyst recyclability, no use of column chromatography and good to excellent yields are extra advantages of this work.

scholarly journals Synthesis of Magnetic Ferrocene-Containing Polymer with Photothermal Effects for Rapid Degradation of Methylene Blue

Polymers ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 558
Author(s):  
Wenhui Zhu ◽  
Caiyun Zhang ◽  
Yali Chen ◽  
Qiliang Deng
Keyword(s):  
Methylene Blue ◽  
Photoelectron Spectroscopy ◽  
Room Temperature ◽  
Degradation Rate ◽  
Model Compound ◽  
Vibrating Sample Magnetometer ◽  
Simulated Sunlight ◽  
X Ray Diffraction ◽  
X Ray ◽  
Ft Ir

Photothermal materials are attracting more and more attention. In this research, we synthesized a ferrocene-containing polymer with magnetism and photothermal properties. The resulting polymer was characterized by Fourier-transform infrared (FT-IR), vibrating sample magnetometer (VSM), scanning electron microscope (SEM), energy dispersive X-ray spectroscopy (EDS), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), and thermogravimetric analysis (TGA). Its photo-thermocatalytic activity was investigated by choosing methylene blue (MB) as a model compound. The degradation percent of MB under an irradiated 808 nm laser reaches 99.5% within 15 min, and the degradation rate is 0.5517 min−1, which is 145 times more than that of room temperature degradation. Under irradiation with simulated sunlight, the degradation rate is 0.0092 min−1, which is approximately 2.5 times more than that of room temperature degradation. The present study may open up a feasible route to degrade organic pollutants.

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