Physics Stack Exchange is a question and answer site for active researchers, academics and students of physics. Join them; it only takes a minute:

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

How can I evaluate the band gap of my ZnO thin film.

Thickness=d=80 nm I’m aware of alpha=-1/d*log(T) But I can’t fit a line to my data. And: How can I smoothen my data on about 346 nm? Do you have any other idea for calculation of band gap from Transmittance and Absorbtion of light by thin films?

h=4.13566733e-15;            %# eV.s 
c=299792458;                 %# m/s 
                             %# landa in (nm) 
nu=c./(landa*1e-9);          %# 1/s 
alpha=-1/(50e-7)*log(T50);   %# 1/cm 
E=h*nu;                      %# eV 

Data: 80.txt

share|cite|improve this question
""have two array lamda Vs Transmittance (T)"" What is this "array"? Do You mean plots? Why two of them? – Georg Apr 23 '11 at 10:05
Data updated... – Abolfazl Apr 23 '11 at 12:42

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Browse other questions tagged or ask your own question.