Photoluminescence vs Absorption

[arnabun]

Hi guys (and girls;))
I need your help...
I really don't get the difference between a PhotoLuminescence and Absorption experiment. What kind of informations one can get from each experiment?
Moreover, why generally photoluminescence experiments are carried on at low temperatures?

Thanks very much,
Biagio

 

[ordinary_girl]

hi
I'm never done the absorption exp before. But I think the process between both experiments is same. the difference is only on the data that you get from the exp.

for e.g., pls refer to this journal (Figure 3 (a) and (b): http://hal.archives-ouvertes.fr/docs/00/22/41/94/PDF/ajp-jphyscol198445C573.pdf

Why at low T?
It's to prevent the electron from thermal excitation. So, you really can make sure that the electron is sitting on the lowest energy level.

*Sorry, my English is not very good.

 

[charng]

Hello Biagio,

Photoluminescence and absorption are two different techniques used to study the interaction of light with matter. In both experiments, a light source is used to illuminate the sample, but the way in which the light is measured and the information obtained from each experiment is different.

In an absorption experiment, the sample is exposed to a broad spectrum of light and the amount of light absorbed at different wavelengths is measured. This provides information about the energy levels of the sample and the transitions that occur between them. Absorption experiments are commonly used to study the electronic structure of materials and can provide information about the presence of impurities or defects.

On the other hand, photoluminescence experiments measure the light emitted by a sample after it has been excited by a light source. This technique is particularly useful for studying the optical properties of materials, such as their band gap energy, as well as the presence of impurities or defects. Photoluminescence experiments can also provide information about the recombination processes that occur within the material.

As for the use of low temperatures in photoluminescence experiments, this is typically done to reduce the thermal energy of the sample and minimize any non-radiative processes that could affect the luminescence signal. This allows for more accurate measurements of the material's intrinsic properties.

I hope this helps clarify the difference between photoluminescence and absorption experiments. Feel free to reach out with any further questions. Good luck with your research!