Kubelka-Munk function Band gap from Diffuse reflectance spectroscopy (DRS)

How to calculate band gap from Diffuse Reflectance spectroscopy (DRS) using kubelka munk function
we will plot (F(R)hv)^2 vs hv
where hv is the energy term in which v is frequency and h is planks constant
and F(R) is the kubelka munk function = k/s
where k is the Molar absortpion coefficient K= (1-R)^2
R is the reflectance data from the Diffuse relflectance spectroscopy DRS data
and S is the scattering factor
S= (2R)
Lets calculate band gap from DRS data
hv is Energy
F(r)hv is kubelka munk function times energy
Now taking squre of this F(R)hv
The standard equation is (F(r)hv)^1/n = A(Eg-Hv)
Almost similar to tauc relation where n have differenct values for direct and Indirect band gap materials.
Now we will plot hv on x-axis
and F(r)hv)^2 on y a-xis for band gap calcualtion
Plotting in origin
2.126 is the band gap
Thank you for watching and Don't forget to subscribe easyedu
#bandgap #DRS #nanoparticles #thinfilms #kubelkamunkfunction #taucrelation

[@Gamster420]

Thanks for this, Amjad.

[@liviasottovia2723]

Thank you for the video!!! It really helped me!!!

[@easyedu1]

You are most welcome

[@user-hk2vo6bg1o]

hello thank you so much for all your effort, just on point maybe you want to use (Fhv)^1/2 instead of (Fhv)^2

[@Azt28Cme]

Thanks for the video, i really want to know how you asume that the F(r) it's equal to the ratio k/s and why to calculate K and S you did thoose operations. If you coul add your biblography it would be very nice from you part. THANK'S AGAIN for your contribution

[@Ali-hm2hh]

Спасибо большое

[@EnglishAddiction]

Appreciate your help!

[@easyedu1]

thank you

[@renansessa8173]

Thank you so much!!!!

[@easyedu1]

You are most welcome

[@AsgarAli-yl5yu]

Appreciate your efforts. I have one query. if I have to perform DRS in solution, what should be the concentration of the solution?

[@MelodicRiddles]

Hello sir... The video is good but I have only one doubt whether this 2 is for indirect bandgap or for direct bandgap? Can you please tell me if we use 2, which bandgap will we get and if we use 1/2, then which bandgap will we get?

[@dedukahopkinsinstitute8063]

I am getting band gap less than what i should get. I shouod be getting 3.9 ev but i am getting 3.2. Any idea

[@smile_nhocpro1553]

My sample is Tio2, coating on metal film, therefore, i use the Reflection is correct right?

[@easyedu1]

If you have reflectance / reflection data from diffuse reflectance spectroscopy (DRS) then yes follow the procedure.

[@ap_sp]

Thank u

[@easyedu1]

Most welcome

[@tathanhhoaiqui1488]

thanks for you video, can I use this Kubelka munk function from UV-vis absorbance?

[@easyedu1]

I think you can use directly tauc equation , we already have a video on calculating band gap from absorbance data with tauc equation UV vis absorbance data just search for that in the videos section

[@snehareddy4826]

Hello, thanks for the video. Is this method applicable for specular reflectance? Also, From the tauc plot (alpha h v)2 vs (hv), how can we measure the energy band gap if we have multiple peaks? I mean it’s difficult to choose a point to extrapolate if we have multiple peaks. So, how can we decide?

[@snehareddy4826]

Please respond

[@easyedu1]

there is no specific rules for this show you data some expert , the peaks occurs due to absorbance of light , which results in the band gap, as the photos energy is used in electron hole pair formation

[@md.sydulislam4362]

Please sir make a video on How to calculate PORE SIZE, PORE DIAMETER from SEM images using ImageJ software.. Please!

[@deekshashakya3647]

Thankyou for the vedio. its very helpful. can you please tell me the unit for y axis ??

[@easyedu1]

I think unit is already written there check in graph or take from any Drs data graph

[@mayanngwynethansino4717]

Hello! Just a question, I hope you see this. I tried plotting my reflectance data using the Kubelka-Mink function to get the band gap. However my graph doesn't look like the one you've generated. It looks more like an xrd data, and I don't know how to get the band gap from that. I used drifts for getting the reflectance values btw, if it makes any difference.

[@easyedu1]

You can try to calculate it from absorption data also there is a video I can watch. And no you might watch the videos again I don't know why your chart looks like xrd as this is completely different chart then the xrd chart

[@mayanngwynethansino4717]

@@easyedu1 it has sharp peaks rather than broad ones.

[@dilek188]

@@mayanngwynethansino4717 Hello I was wondering If you find the solution for this I also have the same problem

[@mayanngwynethansino4717]

@@dilek188 I still have to get my absorption data from the lab and try to use that instead. However, I did try fitting my reflectance data into a gaussian curve and it gave me the right graph when I transformed it using K-M function. The downside is, the Eg values I had calculated were inconsistent for my nine samples. I still have to figure it out.

[@dilek188]

@@mayanngwynethansino4717 I understand. Thank you so much

[@saarthakshrivastava5559]

you didn't mention if it is direct or indirect band gap

[@ayeshazareen41]

hi... is this possible to convert reflectance data of DRS to trasmittance??? if yes then plz guide

[@easyedu1]

You need Uv-vis for absorption and transmittance data.

[@kevinjty]

Hi just wondering how can I obtain reflectance from DRS. I already have transmittance data.

[@easyedu1]

If you transmittance ( the reflectance is usually from diffuse reflectance spectroscopy DRS and transmittance or absorbance is from UV vis) than convert that to absorbance and using tauc plot calculate band gap ( for converting transmittance to absorbance( and then calculate band energy) watch our today's video check in the videos of this channel)

[@kevinjty]

@@easyedu1 Thanks for replying. after watching the latest video, I can convert the transmittance to absorbance, then how can I obtain bandgap from absorbance data?

[@easyedu1]

Watch another video of this channel (how to calculate band gap from UV Vis absorbance spectra their are also some other videos) use tauc relation plot (ahv)power 1/n verses hv Alpha is absorption coefficient h is hv is energy, then draw the line with the curve to pick the energy value.