Dear Sutapa Badyakar

Please take help from the following article:

https://www.ias.ac.in/public/Volumes/sadh/044/01/0026.pdf.

In addition, please refer to the following discussion on RG:

https://www.researchgate.net/post/What-is-Urbach-Energy-and-How-it-arises-Source-of-Urbach-Energy

In the following research article of mine, details are provided for calculating urbach energy. Also relevant concepts are discussed.

Article Size-modulation of functionalized Fe3O4: Nanoscopic customiz...

Plot the graph between ln (alpha) versus photon energy, then take invése of the slope which gives the urbach energy and intercept give the value of alpha0. Where, alpha=(2.303*abs)/ film thickness and photon energy=hc/lamda

Hi Sutapa Badyakar

Urbach energy is the energy that gives the spectral dependence of the absorption coefficients that are examined at photon energies, which are less than the bandgap of the material. It is used to quantify energetic disorders in the band edges of semiconductor material. For the bandgap measurement, you have to do the UV-DRS study of material and the bandgap will be evaluated from Tauc's method. To evaluate the Urbach energy the Eq. ln α = ln αo + (hν/EU) can be used, where EU can be obtained from the slope of the straight line of plotting ln (α) vs. the incident photon energy (hν). The alpha (α) value can be calculated from Tauc's method. For information about Tauc's method, several works of literature are available. I can suggest the above from my point of view.

Regards

Please see the following link:

https://www.youtube.com/watch?v=7tHmqn3qmxQ&list=PLDXoYGTyDkIWojgzQK2k8EQKBrCvOjboe&index=2