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.