How to calculate band gap energy from UV-Vis reflection (DRS) data in origin

#bandgapenergy #originpro #sayphysics
0:00 how to calculate bandgap energy from UV-Vis reflection (DRS) data in origin
1:15 band gap calculation from DRS data in origin
3:00 band gap energy using Kubelka Munk function (DRS data) in origin
4:50 band gap calculation using Kubelka Munk function on DRS data
6:55 diffused reflectance spectroscopy data bandgap calculation
8:10 band gap (Eg) of UV-Vis reflection data using Tauc plot
10:30 band gap (Eg) calculation of UV-Vis reflection spectra
Exercise File (Origin File):

In this YouTube video, viewers will learn how to calculate the band gap energy of a semiconductor material using UV-Vis reflection (DRS) data in Origin software. The video will begin by providing a brief overview of band gap energy and its importance in materials science and engineering. Next, the presenter will demonstrate how to import and process the DRS data in Origin, and create a Tauc plot by plotting (αhν)^2 as a function of photon energy (hν). The linear portion of the curve will be identified and extrapolated to the x-axis intercept to determine the band gap energy. Throughout the video, the presenter will provide helpful tips and explanations to help viewers understand the process and troubleshoot common issues. By the end of the video, viewers will have a clear understanding of how to calculate band gap energy from UV-Vis reflection data in Origin, which can be applied to a wide range of materials research and development projects.

"Band gap energy calculation" "UV-Vis reflection data analysis" "DRS data analysis" "OriginLab tutorial" "Data plotting" "Spectral analysis" "Optical properties of materials" "Semiconductor characterization" "Electronic band structure" "Absorption spectroscopy" "Optical absorption spectra" "Energy bandgap measurement" "Material science analysis" "Quantitative analysis" "Spectroscopic techniques" "Thin film characterization" "Electronic properties of materials" "Photovoltaic materials" "Spectral data processing" "UV-Vis spectroscopy analysis"

All UV-Vis Analysis Video Tutorials:
1. How to calculate band gap energy from UV-Vis absorption
2. Calculate band gap energy from UV-Vis absorbance
3. How to calculate band gap energy from UV-Vis reflection (DRS) data
4. How to calculate band gap energy from photoluminescence (PL) data
5. Band gap energy with baseline correction using Tauc plot from UV-Vis absorbance data
6. How to estimate the size of nanoparticles from UV-Vis absorbance data
7. Nanoparticle size, morphology, concentration and distribution from UV-Vis absorbance data
8. Calculate concentration from UV-Vis absorbance using Beer-Lambert's law
9. How to calculate Urbach energy from UV-Vis absorbance data
10. How to plot and normalize FTIR and UV-VIS data
11. Absorption coefficient α calculation from UV-Vis absorbance data

Reference article:
Bibliographical review for reflectance of diffusing media

How is band gap calculated from UV-Vis reflectance spectra?
How do you find the band gap from the UV-VIS result?
How is band gap energy calculated?
How do you find the energy band gap of a semiconductor?

Tauc used an equation in 1968 to calculate the absorption edges (bandgaps) of amorphous Ge and Si from their absorption data.
(αhν)γ=A(hν-Eg)
In this equation, α is the absorption coefficient, h is Planck’s constant, υ is the frequency of the incident photon, A is a proportionality constant (which is determined by the index of refraction, electron, and hole effective masses; however, it is usually taken as 1 for amorphous materials), and Eg is the bandgap energy. The important term is the exponent γ, which denotes the nature of the electronic transition, that is, when
γ=2 it is a direct allowed transition, and when it is equal to 1/2, it is an indirect allowed transition.
For γ=2/3 it is a direct forbidden transition, and for γ=1/3 an indirect forbidden transition.
Typically, the allowed transitions dominate the basic absorption processes, giving either direct or indirect transitions.
Thus, the basic procedure for a Tauc analysis is to acquire optical absorbance data for a sample in question that spans a range of energies from below the bandgap transition to above it.
Plotting the (αhν)γ versus (hν) is a matter of testing γ=2 or γ=1/2 to compare which provides
the better fit and thus identifies the correct transition type.

[ashfaqahmad]

Thank u so much, dear sir. You have set aside a few minutes for the day's task.

[mayernashat]

You have helped me in my graduation project. God bless You.

[kumarshivesh]

Thanks, Dr. Shahid Ali Sir for another useful video on bandgap calculation.

[MrMRbarati]

Excellent presentation. Thanks for sharing and deciding your time to learn us. God bless you. 🙏🌸

[Almeidov]

Thank you so much. Very good explanation.

[namrathanammu]

Hello Sir,
I'm Namratha from India. Now I have started my PhD journey. For UV-related things, I always refer to your video. I wrote one paper(UV part) based on your Tacu plot video. Thank you for sharing your knowledge. I have one doubt in this video. I have wavelength and reflectance, and I can find an energy gap. But can I calculate absorbance from reflectance? I referred many papers but I didn't get the answer. One says it's A=1-T while others say it's A=1-(R+T). Here I don't have the transmittance and absorbance data. How can I calculate absorbance?
In case we don't calculate absorbance from UV DRS data. Can you please send me one research paper that includes all your explanations? I need to write the reference.

[Kasen-lc]

Thank you for your explanation. I just have one more question. If my material is direct, should I use (F(R)hv)2 or (F(R)hv)1/2? It should be the former one according to the absorbance video but there is no specific explanation in the reflectance one. It should be the same right? Thank you!

[ibrahimnazemqader]

Thanks. The minimum y-axis should be 0, then the extrapolation line is correct.

[antonioculebro]

Sir, I have an existential doubt and I would really appreciate your prompt response, why are the units Ev*cm-1? I am confused, the wave number is the inverse of the wavelength, but when dividing 1240 / nm, we do not have Ev*cm-1, please explain to me. :(

[yuwarajkhatri]

The bandgap seems to be wrong because the origin of the vertical axis has not been set at zero. Vertical axis MUST start from zero. Otherwise the tangent line intersects the horizontal (eV) axis at a point less than the actual bandgap.

[Powolice]

since both the direct and indirect bandgap looks the llinear you concluded that this is qusai direct bandgap then use indirect bandgap. Is this always true where when the direct and indirect looks the same linear you use indirect bandgap?

[shwetachahal]

Can you explain the extra drop in ahv1/2 and ahv2 on higher hv value?
I didn't get it

[montserratdelahoya]

What does F(R) means physically? It's the ratio between k/s but, what is that?

[soniaahlawat]

How can we find which band gap is correct( direct or indirect) ??

[syedraza]

How can you calculate energy in ev where is the absorption A?

[mushahidhussain]

Wonderfull Sir, Sir kindly make vedio to calculate Response and Recovery time, and hysteresis loop calculations.

[kagakuyy]

what the significant different ahv2 and ahv1/2, sir?

[snehareddy]

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?

[MuhammadIsmail-yqqq]

Waiting for QM lectures
Which subject u will upload in this semester

[gauravrajak]

some people asking about the normalizing of K-M functions in comments, why do we need to normalise and when to.