I ran an experiment using translucent single crystal solids. I modified the solids along the way using different chemical/temperature environments. After every stage, I ran the samples through a UV-VIS spectrometer (maybe it was technically a spectrophotometer, I'm a bit confused by the distinctions.
This spectrometer showed a beautifully clear difference in my absorption spectrum that appears to match up with what I am seeing in the other tests and properties of the samples. Namely, as I increase the temperature/chemistry of the modification, the absorption increases across different wavelengths and the cutoff frequency - the frequency at which everything is absorbed - increases from the UV range to the visible range.
My question is two fold:
(1) The formulas I am finding to get the information I need - such as band gap information - appear to rely on the sample being suspended as particles in some medium. My sample is a solid sheet of material about 0.5mm thick. The cuvette that I have been using is 1cm thick, leaving room for my sample to rattle about (though I took pains to make sure it was in the same position each time). How do I go about converting the suspension formulas to something I can use on my solid?
(2) This is more to save me some time and a favor owed: Given that you know how to answer (1), can you give me a general way to get band gap information out of this data from a solid?