I want to measure the type and work function of Beta Gallium oxide. Unfortunately I dot not have access to UPS or Kelvin probe set up. Is there an indirect method to measure the work function of the material?
I think you can do it indirectly by performing electrical measurement like the capacitance-voltage. Make schottky and ohmic contact on the device and measure the capacitance-voltage. From there calculate 1/c2-V and calculate the doping concentration. From this value calcupate the fermi level with respect to conduction band. And finally add this level with the electron affinity of the semiconductor. This will give you the work-function.
Regarding the previous two suggestions involving Schottky and Ohmic contacts - while these can be powerful methods, both assume that no Fermi level pinning (FLP) exists at the interface and that you can assume a perfect Schottky or Ohmic contact. In practice, this is often not the case and FLP can dominate the transport, making the interpretation challenging-to-impossible.
From a similar category I could suggest making a simple MOS structure and obtaining the WF from PHI_MS obtain from different insulator thicknesses, but then again - FLP can exist here as well (studies into the FLP of this material could be of significant importance if none were conducted so far).
In the absence of KP and UPS (and collaborators with such instruments) perhaps you could consider STM with in-situ cleaving of the sample. I'm not very familiar with the details but under some conditions the WF can be extracted from the local I-V behavior.
I agree with the researchers above . However, i would like to mention to Remi, that in practice the method he suggested gives generally wrong EWF measurements for any metallic sample, because of contact potential difference between the electrodes. I have used it at the beginning of my research works. Fowler method gives much more reliable and accurate results.
You can take a look to my thesis, on page 66, in the following link :
https://www.researchgate.net/publication/306307509_Ph_D_Thesis_DETERMINATION_PHOTOELECTRIQUE_DU_TRAVAIL_DE_SORTIE_DES_MATERIAUX_DE_CONTACT_SUIVANT_LEUR_UTILISATION_INDUSTRIELLE?ev=prf_pub
Data Ph. D. Thesis : "DETERMINATION PHOTOELECTRIQUE DU TRAVAIL DE...
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