Usually insulators have more band gap than the semiconductors. people use to measure the temperature variation of resistance of the insulators (ex. oxides) and fit the data with an activation energy. At this point, is it possible say that the band gap of the material is equal to this activation energy?
Hi,
i agree with Driss if your band gap material is not too high of course. For high band gap material (>6 eV e.g., SiO2, Al2O3), then you'll need a vacuum UV (or synchrotron) setup which may be more complex.
@ Driss: If the sample is thin film, one could have enough intensity to measure transmittance spectrum of the sample. But, If the sample is enough thickness (Bulk), then the intensity falls or absorbs before going to transmittance. In this context, how to plan your experiment to find out its band gap....?
@ Ali : It is very helpful for me if you provide any reference articles or information about the standard books to find out the details of the vacuum UV or synchrotron experiment.
Before to use any VUV set up, could you please tell us what is your WBGM ?
also what do you mean by bulk ? is your film or wafer thicker than 500 or 750 micron ?
If yes, is it still transparent (in the visible) ? Depending on the quality of your WBGM, thick film (or bulk) can still be characterised optically.
BTW here is the link to the reference paper (PTB facility that i'm using for VUV-NUV characterisation):
https://www.researchgate.net/publication/235218634_Current_capabilities_at_the_Metrology_Light_Source
Article Current capabilities at the Metrology Light Source
For the very large bandgap semiconductor, i think you should use the reflectance spectra or transmittance spectra. In your case, it is bulk insulator, so measure reflectance spectra is more convenient.
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