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hole mobility by IBTE

Posted: Thu Oct 13, 2022 8:41 am
by mishchenka
Dear all.

My question concerns simulation of hole mobility using iterative solution of Boltzmann equation for C2H2 structure. The programs QE-7.0 and EPW-5.4.1 were used. In the appendix there are three files which reflect features of modeling. I can send the other files, which I used in modeling, in the additional letter. Analysis of the file C2H2A.epw.out shows, as it seems to me, an abnormal, overestimated value of hole mobility (order approximately 1d+05) for this structure. Also does not correspond to the initial data value of the parameter Hole density (0.136d+21). Separately requires attention to the value of the parameter Population SR, I do not know whether this parameter corresponds to normal values. I tried to change the values of the parameters fsthick and degaussw, but this did not change the results, either fixing mobility values that are similar to those mentioned above, or fixing error in the simulation. Phonon calculations using the C2H2.ph.in file were performed with the parameters tr_2ph = 1d-14 and for a 12x12x1 grid.
Similar simulations were performed for the electrons in this structure. With similar input values, electron mobility values of approximately 95 (124) were obtained when SERTA was used and approximately 135 (179) when the IBTE solution was used. I am interested in what can be caused such big difference in values of mobility of holes and electrons, where I made a mistake in the input parameters of the simulation.

Thanks for the answer!

Best regards,
Mishchenka Valery.
Associate Professor, Ph. D.,
Belarusian State University of Informatics and Radio Electronics