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Thanks to this lovely website, I was able to pop out reasonable values for my band gap energies from a translucent material. As expected, I found a decrease in band gap energy due to my treatments.

Now, I also need some numbers put to dopant concentration. My dopants, in this case, are reduced forms of the semi-conductor material I am treating, but I think the concept can be generalized to all dopants. So my query is as follows:

If I know how the band gap changes between a doped and undoped material, is there a formula that will give me the amount or density of the dopants in the material? For example, say my band gap before doping was 3.0eV and after doping it was 2.5eV, can I pull out how many dopant atoms were added to my material?

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To my knowledge, a general formula does not exist. The modification of the band gap heavily depends on the doped material and the dopant.

For moderate dopings, there seems to be an answer on this link I found with a quick google search :

Look at section This might fall into what you are trying to do.

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