Jove
Visualize
Contact Us
JoVE
x logofacebook logolinkedin logoyoutube logo
ABOUT JoVE
OverviewLeadershipBlogJoVE Help Center
AUTHORS
Publishing ProcessEditorial BoardScope & PoliciesPeer ReviewFAQSubmit
LIBRARIANS
TestimonialsSubscriptionsAccessResourcesLibrary Advisory BoardFAQ
RESEARCH
JoVE JournalMethods CollectionsJoVE Encyclopedia of ExperimentsArchive
EDUCATION
JoVE CoreJoVE BusinessJoVE Science EducationJoVE Lab ManualFaculty Resource CenterFaculty Site
Terms & Conditions of Use
Privacy Policy
Policies

Related Concept Videos

Molecular Spectroscopy: Absorption and Emission01:14

Molecular Spectroscopy: Absorption and Emission

Molecules possess discrete energy levels called quantum states. Unlike atoms, which have simpler energy levels, molecules possess additional rotational and vibrational energy levels. Each energy level is separated by an energy gap, with the gaps between adjacent electronic, vibrational, and rotational levels varying significantly. The three types of energy levels in a diatomic molecule are shown in Figure 1.
Atomic Spectroscopy: Absorption, Emission, and Fluorescence01:23

Atomic Spectroscopy: Absorption, Emission, and Fluorescence

Atomic spectroscopy is a vital tool in elemental analysis, both qualitatively and quantitatively. It can be broadly divided into optical spectroscopy, mass spectroscopy, and X-ray spectroscopy methods. The optical spectroscopic methods are atomic absorption spectroscopy (AAS), atomic emission spectroscopy (AES), and atomic fluorescence spectroscopy (AFS). The first step in all three methods is atomization, where the solid, liquid, or solution-phase samples are converted into gas-phase atoms and...
¹H NMR: Interpreting Distorted and Overlapping Signals01:02

¹H NMR: Interpreting Distorted and Overlapping Signals

Spin systems where the difference in chemical shifts of the coupled nuclei is greater than ten times J are called first-order spin systems. These nuclei are weakly coupled, and their chemical shifts and coupling constant can generally be estimated from the well-separated signals in the spectrum.
As Δν decreases and the signals move closer, the doublets appear increasingly distorted. The intensities of the inner lines increase at the cost of those of the outer lines as the signals are slanted or...
IR Absorption Frequency: Hybridization01:21

IR Absorption Frequency: Hybridization

Hydrocarbons such as alkanes, alkenes, and alkynes show characteristic C–H stretching absorption bands. These IR stretching frequencies depend on the hybridization of the involved carbon atom and can be explained in terms of the s character of each hybridized atomic orbital.
Among the sp, sp2, and sp3 hybridized orbitals, sp orbitals have the maximum s character (50%). Consequently, the electrons are held more closely to the nucleus, resulting in stronger and shorter C–H bonds that stretch at a...
UV–Vis Spectroscopy: Molecular Electronic Transitions01:16

UV–Vis Spectroscopy: Molecular Electronic Transitions

In Ultraviolet–Visible (UV–Vis) spectroscopy, the absorption of electromagnetic radiation is used to probe the electronic structure of molecules. This technique provides insights into molecular electronic transitions, particularly the movement of electrons between different molecular orbitals. Radiation is absorbed if the energy of the electromagnetic radiation passing through the molecule is precisely equal to the energy difference between the excited and ground states. During this process,...

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by
Same author

Ultra-stable super-resolution fluorescence cryo-microscopy for correlative light and electron cryo-microscopy.

Science China. Life sciences·2018
Same author

MicroRNA-141 binds to the nerve growth factor receptor associated protein 1 gene and restores the erectile function of diabetic rats through down-regulating the nerve growth factor/neurotrophin receptor p75 (NGF/p75NTR) signaling.

Journal of cellular biochemistry·2018
Same author

Elevated IL-33 promotes expression of MMP2 and MMP9 via activating STAT3 in alveolar macrophages during LPS-induced acute lung injury.

Cellular & molecular biology letters·2018
Same author

Exosomes from Thymic Stromal Lymphopoietin-Activated Dendritic Cells Promote Th2 Differentiation through the OX40 Ligand.

Pathobiology : journal of immunopathology, molecular and cellular biology·2018
Same author

Solution-Based Property Tuning of Black Phosphorus.

ACS applied materials & interfaces·2018
Same author

Rapid quantitative analysis of etoricoxib in human plasma by UPLC-MS/MS and application to a pharmacokinetic study in Chinese healthy volunteers.

Biomedical chromatography : BMC·2018

Related Experiment Video

Updated: Jun 21, 2026

High Resolution Phonon-assisted Quasi-resonance Fluorescence Spectroscopy
10:40

High Resolution Phonon-assisted Quasi-resonance Fluorescence Spectroscopy

Published on: June 28, 2016

Shape-dependent two-photon absorption in semiconductor nanocrystals.

Xiaobo Feng1, Wei Ji

  • 1Department of Physics, National University of Singapore, Singapore 117542, Republic of Singapore.

Optics Express
|August 6, 2009
PubMed
Summary
This summary is machine-generated.

We theoretically investigated two-photon absorption (TPA) in semiconductor nanocrystals (NCs). Our findings show that nanocrystal shape significantly impacts TPA, with cuboid and cube shapes exhibiting higher cross-sections due to reduced symmetry.

More Related Videos

Characterization of Nanocrystal Size Distribution using Raman Spectroscopy with a Multi-particle Phonon Confinement Model
06:54

Characterization of Nanocrystal Size Distribution using Raman Spectroscopy with a Multi-particle Phonon Confinement Model

Published on: August 22, 2015

Related Experiment Videos

Last Updated: Jun 21, 2026

High Resolution Phonon-assisted Quasi-resonance Fluorescence Spectroscopy
10:40

High Resolution Phonon-assisted Quasi-resonance Fluorescence Spectroscopy

Published on: June 28, 2016

Characterization of Nanocrystal Size Distribution using Raman Spectroscopy with a Multi-particle Phonon Confinement Model
06:54

Characterization of Nanocrystal Size Distribution using Raman Spectroscopy with a Multi-particle Phonon Confinement Model

Published on: August 22, 2015

Area of Science:

  • Theoretical physics
  • Materials science
  • Quantum chemistry

Background:

  • Two-photon absorption (TPA) is a crucial photophysical process in semiconductor nanocrystals (NCs).
  • Understanding TPA's dependence on NC shape is vital for optimizing optoelectronic applications.
  • Previous studies lacked a comprehensive theoretical framework for shape-dependent TPA analysis.

Purpose of the Study:

  • To theoretically investigate the shape dependence of TPA in semiconductor NCs.
  • To develop an analytical theory explaining TPA measurements in CdS nanorods.
  • To reveal TPA characteristics in CdSe and ZnO NCs across various shapes.

Main Methods:

  • Employed a four-band model within the effective mass approximation.
  • Developed a simple analytical theory for quantitative TPA analysis.
  • Systematically studied TPA in spheres, cubes, cylinders, and cuboids of CdSe and ZnO.

Main Results:

  • Nanocuboids and nanocubes show greater TPA cross-sections than nanocylinders and nanospheres, respectively, due to symmetry-induced energy level splitting.
  • Nanocuboids and nanocylinders exhibit larger TPA cross-sections than nanocubes and nanospheres of similar lateral dimensions.
  • TPA cross-section in nanocuboids demonstrates stronger size dependence than in nanocylinders, with lateral size being more influential.

Conclusions:

  • Nanocrystal shape is a critical factor governing two-photon absorption efficiency.
  • The developed theory quantitatively explains experimental TPA measurements.
  • Tailoring NC shape offers a pathway to control and enhance TPA properties for advanced applications.