QuantumATK Forum
QuantumATK => General Questions and Answers => Topic started by: ams_nanolab on December 27, 2012, 12:45
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Dear Sir,
I was evaluating the electron and hole effective masses in monolayer MoS2 using the effective mass analyzer. However I am finding some results to be quite surprising. The electron eff mass in the K-->Gamma direction is about 0.540 but the hole effective mass in the same direction is showing 2.002. The same trend is seen in other directions like K--> M etc. This is rather odd as the curvatures of the bottom CB and the top VB at K point seem quite similar from the bandstructure. Also a recent paper [http://prb.aps.org/abstract/PRB/v86/i24/e241401] on effective masses in monolayer MoS2 shows the electron and hole effective masses to be quite close for relaxed monolayer.
In our calculation we are following the tutorial
http://quantumwise.com/publications/tutorials/mini-tutorials/135
and setting the value of Relative Band Index = 0 for electrons and -1 for holes.
Could you elaborate what is wrong?
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There is usually more than one hole band so you can try -2 and -3 as well. Otherwise you have to look at the band structure to see if they are accurate with the given method used for the calculation (Huckel, DFT, whichever).