Question

Relation between energy gap and refractive index of tungsten oxide films

Answer 1

No single equation correlating all the three quantities was reported in literature. However, the three parameters are indiectly related as:

R= (n-1) ^2+k^2/ (n+1) ^2+k^2. ------ [i].

Here R is reflectivity and n is refractive index and k is the extinction coefficient.

R+A+T=1 --------- [ii] and

k= α. λ/4π ----- [iii]

α. (optical absorption coefficient) = 2.303A/t--- (b) – [iv].

A is absorbance and t is thickness of film.

Also,

α = (h. ν -Eg) ^1/2 -----[iv].

Eg is band gap.