Band Gap Eg calculation from Photoluminescence (PL) Spectra

[@ms.cmozahimazizalamery7880]

Good night Thank you for the clarification Please how can I explain the energy gap quantities that have been calculated based on the wavelengths of the PL spectrum obtained using the optical luminescence spectrum Please clarify that

[@dhanalakshmib4281]

Is this emission peak or Exicitation peak?

[@dineomolebatsi1470]

my question exactly

[@candoga]

What is the reason of the 1st peak in your graph?

[@easyedu11]

are you talking about the first straight peak near 320 nm ?

[@candoga]

@@easyedu11 Yes. Sorry, Iim very new to this concept and these type of measurements so I needed to ask.

[@easyedu11]

The first sharp peaks is due to laser that is not a peak

[@candoga]

@@easyedu11 Got it! Thanks a bunch :)

[@fadurecipes]

@@easyedu11 Hello sir Which laser, laser inside PL spectrometer?

[@xwj8245]

Thanks for your introduction! I literally understand what is photoluminescence spectra! I appreciate your help! But do you know how to do this experiment? Can you give me a tip?

[@easyedu11]

this can be done with Photo luminescence spectrometer, some times fluorescence machine can also get the pl result and in our lab we did this and raman with the same machine in our lab

[@balamsemiconductor]

This is no true because you can have donors or aceptors which reduce the emission and are not the band to band transition.

[@easyedu11]

luminescence is the recombination of electrons and hole from conduction and valence band. sir could you explain little more i am not getting,

[@phdthoughts8404]

I am also convinced that we can use it to measure Band gap by this way? As I was struggling with a situation where my material does not show any absorbance in Visible region but it can excite with green blue light and emiit green and red color

[@pallabcm]

@@phdthoughts8404 Hi, did you find your answer? I am also struggling to find it. My material is yellow and it turns green in pure visible light. But I got both the UV absobance peak ( one in UV and other in visible region).

[@aymanzaki2865]

I need reference for this calculation, urgently needed

[@easyedu11]

It is a common method search on Google scholars you will find many references but this is no a very reliable because the peak may be due to the recombination of excitons or this band gap might be slightly less than the original method, or the emission might be due to some impurities vacancies so the best option is to measure the band gap from UV vis data or from drs diffuse reflectance spectroscopy, using the tauc equation videos on both methods drs kubelka-munk and UV vis band gap calculations are available in this channel those videos might be helpful for you, the pl band gap will confirm the wavelength and band gap value with drs and UV vis.

[@danyalkhan6580]

Nice one

[@sikanderhayat988]

I think this is not the right way to calculate the band gap.

[@easyedu11]

You can follow kubelka mulk fiction or absorbance data and using touc equation will give u the correct band gap value, videos are available for both of those methods in this channel