Question

How to calculate band gap fr nanomaterials by uv visible method?

Answer 1

Answer:

The band gap energy can be determined from wavelength at which a steep raise is initiated in absorbance. This is due to the fact that the measured wavelength of photon is the minimum required for electron excitation across the band gap. However, the accuracy of this approach can be put to question by prevalence of non linear absorbance increase that depends on the presence of defect sites and local density of states at the valance and conduction band edges.

An ideal approach for exhaustive band gap analysis would involve the use of Tauc plots for fitting of absorption coefficients to match the expected trends of direct and indirect band gap semiconductors. The absorption coefficient α can be calculated from path length l and absorbance A using the following formula.

α(cm^(-1) )=(ln(10)×A)/(l(cm))

With the use of absorption coefficient α, base line extrapolation of Tauc plots specific to direct and indirect band gap determination can be employed for computation of band gap energies (Where hυ=E, the energy gap, so general trends are to be known to assume determine x and y axes E)

PLEASE MARK AS BRAINLIEST......

Answer 2

Explanation:

please write question correctly

I don't understand