Incandescence and electronic excitation

  • Context: Graduate 
  • Thread starter Thread starter hokhani
  • Start date Start date
  • Tags Tags
    Electronic Excitation
Click For Summary

Discussion Overview

The discussion centers around the phenomenon of incandescence and its relationship to electronic excitation in various materials, including conductors and insulators. Participants explore the underlying mechanisms and conditions that lead to incandescence, particularly in the context of thermal energy distribution and electronic states.

Discussion Character

  • Exploratory
  • Technical explanation
  • Conceptual clarification
  • Debate/contested

Main Points Raised

  • One participant notes that incandescence occurs in a wide variety of materials, questioning its relation to electronic excitation.
  • Another participant explains that at equilibrium, thermal energy is distributed among all degrees of freedom that are not "frozen," including electronic degrees of freedom at high temperatures, leading to emission across a broad spectrum.
  • A different participant raises a question about how insulators can exhibit incandescence despite their large energy gaps preventing electron excitation at lower temperatures.
  • It is mentioned that states are populated with a probability related to the Boltzmann factor, indicating that thermal electronic excitation can occur, particularly at elevated temperatures where it becomes significant enough for incandescence to be observed.

Areas of Agreement / Disagreement

Participants express differing views on the role of electronic excitation in incandescence, particularly concerning insulators. There is no consensus on how insulators can exhibit this effect given their electronic structure.

Contextual Notes

Some assumptions about the behavior of electronic states in different materials and the conditions under which incandescence occurs remain unresolved. The discussion also highlights the complexity of thermal energy distribution and its implications for various materials.

hokhani
Messages
601
Reaction score
22
As far as I experienced, incandescence happens in a wide variety of materials no matter what a substance (conductor, insulator and so on) is. Does this effect is related to the electronic excitation? Could anyone please explain the reason of this effect?
 
Physics news on Phys.org
At equilibrium, the thermal energy is spread out into all degrees of freedom that are not "frozen" (i.e., for which there is enough energy to lead to a significant population of the excited states). For high enough T, that includes electronics degrees of freedom. In the solid state, electronic states usually constitute continua, such that emission is over a wide range of the electromagnetic spectrum.

You should look up blackbody radiation.
 
DrClaude said:
At equilibrium, the thermal energy is spread out into all degrees of freedom that are not "frozen" (i.e., for which there is enough energy to lead to a significant population of the excited states). For high enough T, that includes electronics degrees of freedom.
In an ideal insulator electrons can not pass the large gap by thermal energy and so there is no electron excitation. How does an insulator show this effect?
 
States are populated with a probability proportional to ##e^{-E/kT}##. There is always some thermal electronic excitation, even though it can be neglected in most cases. But there is always a point where the temperature is high enough that it is not negligible anymore, and the object will glow.
 

Similar threads

Graduate "Cross-section" and "half-life" of excited states
  • · Replies 3 ·
Replies
3
Views
2K
Graduate Photons through transparent materials, what's going on?
  • · Replies 22 ·
Replies
22
Views
8K
High School Electrostatic charge build up in environmental electron microscopy
  • · Replies 7 ·
Replies
7
Views
2K
High School How does lattice vibration affect electron mobility in semiconductor?
  • · Replies 1 ·
Replies
1
Views
2K
Graduate Excitation Effects for Fluorescence Spectroscopy
  • · Replies 6 ·
Replies
6
Views
3K
Graduate Thermal excitation of electrons in semiconductors
  • · Replies 3 ·
Replies
3
Views
8K
Graduate Deriving the perturbative expansion from Hubbard to Heisenberg
  • · Replies 0 ·
Replies
0
Views
2K
Graduate Question about a measured spectra
  • · Replies 7 ·
Replies
7
Views
2K
High School What happens to excess energy when an electron gets excited by light?
  • · Replies 7 ·
Replies
7
Views
2K
Undergrad Continuous Spectrum and Energy levels of Electrons (Energy Bands)
  • · Replies 7 ·
Replies
7
Views
3K