Arrhenius plot and activation energy

[prehisto]

Hi,guys.
I m trying to determine activation energy of donor levels .
So i have measured absorption at different temperatures of my sample (mono-crystal)

And I have plotted ln(optical density) vs 1/T(K).
And I want to calculate activation energy useing
D=D₀exp(-E_a/kT)

In plot above (picture) E_activation should be 0.043eV

The problem is that I can't get the right answer.
Could someone help me,and derive the mentioned formula above for Ea determination? Maybe I am doing it wrong.

 

[Useful nucleus]

Hi prehisto,

First the scatter in your data should make a large error bar. What is the 95% confidence range of this fitted activation energy?

Second, I would check things like natural log v.s. decimal log and the units of Boltzmann constant, just the basic stuff.

 

[prehisto]

I agree, it makes a large error bar. But in this case it does not matter . This is an example for which i know the result ( for this particular liner fitting).

i have checked logarithms and Boltzman const.

Is this the correct formula?