Photoluminescence Spectroscopy
Photoluminescence Spectroscopy - Related Videos
01:14
Photoluminescence: Applications
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2024
Photoluminescence offers a wide range of applications due to its inherent sensitivity and selectivity. This technique allows for both direct and indirect analyses of the analyte. Direct quantitative analysis is possible when the analyte exhibits a favorable quantum yield for fluorescence or phosphorescence. However, an indirect analysis may be feasible if the analyte is not fluorescent or phosphorescent, or if the quantum yield is unfavorable. Indirect methods include reacting the analyte with...
10:40
High Resolution Phonon-assisted Quasi-resonance Fluorescence Spectroscopy
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Cited by 2 •
2016
The manuscript describes a method of phonon-assisted quasi-resonant fluorescence spectroscopy that incorporates both laser-limited resolution and photoluminescence (PL) spectroscopy. This method utilizes optical phonons to provide linewidth-limited resolution spectra of atom-like semiconductor structures in the energy domain. The method is also easily realized with a single spectrometer optical spectroscopy setup.
01:23
Photoluminescence: Fluorescence and Phosphorescence
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2024
Photoluminescence is a process where a molecule absorbs light energy and re-emits it in the form of light. This phenomenon occurs when a substance absorbs photons, promoting its electrons to higher energy level excited states, followed by a relaxation process in which the electrons return to their original ground state energy levels and emit light. Photoluminescence is widely observed in various materials, including semiconductors, and organic and inorganic compounds. A pair of electrons in a...
09:21
Mössbauer Spectroscopy
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2023
Source: Joshua Wofford, Tamara M. Powers, Department of Chemistry, Texas A&M University Mössbauer spectroscopy is a bulk characterization technique that examines the nuclear excitation of an atom by gamma rays in the solid state. The resulting Mössbauer spectrum provides information about the oxidation state, spin state, and electronic environment around the target atom, which, in combination, gives evidence about the electronic structure and ligand arrangement (geometry) of the molecule.
08:11
Infrared Spectroscopy
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2023
Source: Vy M. Dong and Zhiwei Chen, Department of Chemistry, University of California, Irvine, CA This experiment will demonstrate the use of infrared (IR) spectroscopy (also known as vibrational spectroscopy) to elucidate the identity of an unknown compound by identifying the functional group(s) present. IR spectra will be obtained on an IR spectrometer using the attenuated total reflection (ATR) sampling technique with a neat sample of the unknown.
FAQs
The measured emission spectrum can be interpreted as a map of radiative relaxation between electronic energy levels. Excitation first places electrons in higher-energy states, and the wavelengths recorded as they return to lower-energy states reflect those transitions. This makes spectral position a useful indicator of electronic structure in the material.
Photoluminescence spectroscopy can pair an emission spectrum with an excitation spectrum to examine the same emissive system from complementary angles. The emission record emphasizes the light released during relaxation, whereas excitation measurements help relate the observed luminescence to the photons used to promote electrons. Together, these measurements strengthen interpretation of energy-level behavior.
Changes in emission intensity or wavelength are chemically informative rather than merely instrumental variations. They can signal changes in molecular interactions, defects, or the surrounding chemical environment, allowing investigators to compare how a material or compound responds under different conditions. This sensitivity is why photoluminescence spectroscopy is useful for studying environmental effects and chemical sensing.
A basic measurement begins by exposing the sample to photons that provide the excitation energy. The emitted light is then collected and recorded as an emission spectrum; excitation spectra may also be acquired for comparison. Researchers can evaluate spectral wavelength and intensity, then relate those observations to electronic structure, interactions, defects, or environmental changes.
In chemistry, the technique is applied to fluorescent and phosphorescent molecules, semiconductor materials, and coordination compounds. The same measurement strategy therefore spans molecular and materials research, while preserving a common focus on emissive behavior. Results can support characterization of electronic structure, chemical environment, molecular interactions, and defects across these different systems.
Photoluminescence spectroscopy supports chemical sensing, materials development, and investigations of reaction or environmental effects on emissive systems. Interpreting wavelength together with intensity changes can connect observed optical signals to chemical or material behavior. This makes the method useful for following how emissive properties vary as molecular interactions, defects, or environmental conditions change.