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

Atomic Nuclei: Nuclear Relaxation Processes01:23

Atomic Nuclei: Nuclear Relaxation Processes

686
In the absence of an external magnetic field, nuclear spin states are degenerate and randomly oriented. When a magnetic field is applied, the spins begin to precess and orient themselves along (lower energy) or against (higher energy) the direction of the field. At equilibrium, a slight excess population of spins exists in the lower energy state. Because the direction of the magnetic field is fixed as the z-axis,  the precessing magnetic moments are randomly oriented around the z-axis.
686
Atomic Nuclei: Types of Nuclear Relaxation01:28

Atomic Nuclei: Types of Nuclear Relaxation

334
Nuclear relaxation restores the equilibrium population imbalance and can occur via spin–lattice or spin–spin mechanisms, which are first-order exponential decay processes.
In spin–lattice or longitudinal relaxation, the excited spins exchange energy with the surrounding lattice as they return to the lower energy level. Among several mechanisms that contribute to spin–lattice relaxation, magnetic dipolar interactions are significant. Here, the excited nucleus transfers...
334
Carrier Generation and Recombination01:22

Carrier Generation and Recombination

640
Carrier generation is the process by which electron-hole pairs (EHPs) are created within the semiconductor. In direct-bandgap semiconductors, such as gallium arsenide (GaAs), this occurs efficiently when energy absorption prompts valence electrons to leap into the conduction band, leaving behind holes.
This process is given by the generation rate G and is efficient due to the conservation of momentum between the valence band maximum and conduction band minimum.
Indirect generation involves an...
640
Types of Semiconductors01:20

Types of Semiconductors

673
Intrinsic semiconductors are highly pure materials with no impurities. At absolute zero, these semiconductors behave as perfect insulators because all the valence electrons are bound, and the conduction band is empty, disallowing electrical conduction. The Fermi level is a concept used to describe the probability of occupancy of energy levels by electrons at thermal equilibrium. In intrinsic semiconductors, the Fermi level is positioned at the midpoint of the energy gap at absolute zero. When...
673
The Bohr Model02:18

The Bohr Model

57.1K
Following the work of Ernest Rutherford and his colleagues in the early twentieth century, the picture of atoms consisting of tiny dense nuclei surrounded by lighter and even tinier electrons continually moving about the nucleus was well established. This picture was called the planetary model since it pictured the atom as a miniature “solar system” with the electrons orbiting the nucleus like planets orbiting the sun. The simplest atom is hydrogen, consisting of a single proton as...
57.1K
Fermi Level Dynamics01:12

Fermi Level Dynamics

290
The vacuum level denotes the energy threshold required for an electron to escape from a material surface. It is usually positioned above the conduction band of a semiconductor and acts as a benchmark for comparing electron energies within various materials.
Electron affinity in semiconductors refers to the energy gap between the minimum of its conduction band and the vacuum level and it is a critical parameter in determining how easily a semiconductor can accept additional electrons.
The work...
290

You might also read

Related Articles

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

Sort by
Same author

Structural Diversity and Tunable Emission in Hybrid Organic-Inorganic Copper(I) Bromides.

Inorganic chemistry·2025
Same author

Electrical Control of Polariton Josephson Junctions via Exciton Stark Effect.

Nano letters·2025
Same author

Benchmarking DFT and Supervised Machine Learning: An Organic Semiconducting Polymer Investigation.

The journal of physical chemistry. A·2024
Same author

Molecular transistors as substitutes for quantum information applications.

Journal of physics. Condensed matter : an Institute of Physics journal·2022

Related Experiment Video

Updated: Jul 28, 2025

Scalable Quantum Integrated Circuits on Superconducting Two-Dimensional Electron Gas Platform
05:39

Scalable Quantum Integrated Circuits on Superconducting Two-Dimensional Electron Gas Platform

Published on: August 2, 2019

9.7K

Hot electron relaxation in Type-II quantum wells.

Hua Wang1, Mario F Borunda2, Kieran J Mullen1

  • 1Department of Physics and Astronomy, University of Oklahoma, Norman, Oklahoma 73019, USA.

The Journal of Chemical Physics
|May 30, 2023
PubMed
Summary

Engineering a phonon bottleneck in photovoltaic devices reduces carrier recombination. This study models hot electron behavior under photoexcitation, finding inhibited phonon relaxation creates a more out-of-equilibrium electron distribution for enhanced efficiency.

More Related Videos

Silicon Metal-oxide-semiconductor Quantum Dots for Single-electron Pumping
14:58

Silicon Metal-oxide-semiconductor Quantum Dots for Single-electron Pumping

Published on: June 3, 2015

14.8K
Nanofabrication of Gate-defined GaAs/AlGaAs Lateral Quantum Dots
15:47

Nanofabrication of Gate-defined GaAs/AlGaAs Lateral Quantum Dots

Published on: November 1, 2013

16.3K

Related Experiment Videos

Last Updated: Jul 28, 2025

Scalable Quantum Integrated Circuits on Superconducting Two-Dimensional Electron Gas Platform
05:39

Scalable Quantum Integrated Circuits on Superconducting Two-Dimensional Electron Gas Platform

Published on: August 2, 2019

9.7K
Silicon Metal-oxide-semiconductor Quantum Dots for Single-electron Pumping
14:58

Silicon Metal-oxide-semiconductor Quantum Dots for Single-electron Pumping

Published on: June 3, 2015

14.8K
Nanofabrication of Gate-defined GaAs/AlGaAs Lateral Quantum Dots
15:47

Nanofabrication of Gate-defined GaAs/AlGaAs Lateral Quantum Dots

Published on: November 1, 2013

16.3K

Area of Science:

  • Materials Science
  • Solid State Physics
  • Renewable Energy

Background:

  • Type-II quantum wells in photovoltaic devices spatially separate electrons and holes, reducing recombination.
  • Higher power conversion efficiency requires preserving energetic carriers by minimizing heat loss.

Purpose of the Study:

  • To verify the phonon bottleneck effect using superlattice phonon calculations.
  • To model the steady-state hot electron distribution under photoexcitation.
  • To investigate methods for enhancing carrier energy preservation in photovoltaic devices.

Main Methods:

  • Superlattice phonon calculations to verify the phonon bottleneck.
  • Coupled Boltzmann equation system to model electron and phonon interactions.
  • Numerical integration to determine the steady-state hot electron distribution.

Main Results:

  • Inhibited phonon relaxation leads to a more out-of-equilibrium electron distribution.
  • The phonon bottleneck effect was verified, confirming poor phonon transport.
  • Different behaviors were observed for various recombination and relaxation rates.

Conclusions:

  • Engineering a phonon bottleneck is a viable strategy to enhance photovoltaic device efficiency.
  • Controlling phonon relaxation is crucial for preserving hot carrier energy.
  • The study provides insights into experimental signatures for optimizing photovoltaic performance.