Using that formula (αhʋ ) = A(hʋ -Eg)n. Please give me some excel using to find the band gap.
Kindly do the needful.
Thanks and regards
Harshan
You can find the band gap by using 'Tauc plot'. The band gap 'Eg' can be evaluated by plotting (hʋ) versus (αhʋ)^(1/n) and extrapolating the tangent on the X-axis. The value of 'n' depends on the nature of transition,eg.,n=2 for indirect allowed , (1/2) for direct allowed, 3/2 for direct forbidden and 3 for indirect forbidden transitions, respectively. If you don't know the type of your semiconducting material, plot using all 'n' values, which one will give steeper straight line, mostly the transition corresponds to that particular 'n' value.
'α' is the absorption coefficient, that you have to calculate from absorption spectra using the Beer–Lambert law, A=αbc.
Follow the link
https://www.researchgate.net/post/How_can_I_calculate_the_absorption_coefficient_from_an_absorbance_vs_wavelength_graph
And value of 'n' depends on the nature of transition, that I've explained in my previous answer.
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