Can any one one suggest about this without knowing the affinity value how will I calculate the work function of the semiconductor.. or if is it not possible then plzz give me any valuable suggestions (without experimental)... to calculate the workfunctio..
Most common semiconductors have known electron affinity values which can be found in papers and databases. For semiconductors you'd need to know the doping to find the Fermi level position versus one of the bands and from there using the EA (and Eg) you could get the WF.
For metals I'm not sure what is the meaning of EA, but it should be the same as the WF. You could also find the experimental WF of most metals in several crystallographic orientations in the CRC Handbook and/or the famous JAP paper by H.B. Michaelson (it's the same).
Einstein's Nobel prize winning work "Photoelectric effect" can be used to determine the work function of a material.
One can also use "UV Photoelectron Spectroscopy" or "Kelvin Probe Force Microscopy" techniques to measure the work function of a material.
Thnks for giving answer.. bt still I am having doubt. Bcz the graphene nanomesh is unknown material and graphene is tuneable bandgap material so may be its affinity will vary according to its band gap.... I have Eg value and calculated its carrier concentration. ....
Graphene is a conjugated system, band gap changes with the size. Treat it like a particle in a box problem in 2-D (quantum mechanics). As the size of the box increases, the band gap decreases. Both IE and EA change.
As we know sir graphene is semi metallic in nature but if we create an hole on the graphene sheet it may become a semiconductor, so it will have a bandgap then its affinity or workfunction will change,, So how do we calculate by hand on calculation.... ??
When you say create a hole you mean physically making a hole in graphene or creating a gap between VB and CB???
When you physically make a hole, you are reducing the conjugation length, confining the pi electrons to a smaller dimension, consequently the band gap increases. In analogy to a particle in 1-D box (quantum mechanics), this is equivalent to reducing the size of the box, the gap between the energy levels increases.
EA can be calculated theoretically using quantum mechanics. There are software like Gaussian, Hyperchem etc where these calculations can be performed.
yes sir when we are creating a appropriate hole in atk tool (Quantumwise tool) then we are getting a gap between VB and CB...
can u give me any reference material for this means ho will i calculate by quantum mechanics... ?
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