QuantumATK Forum

QuantumATK => General Questions and Answers => Topic started by: njuxyh on February 28, 2019, 04:22

Title: how to make the PLDOD more smooth?
Post by: njuxyh on February 28, 2019, 04:22

Hi all:
i plot PLDOS of a pn junction and found the PLDOS is not smooth at some region,  it is unphysical, because the smoothless region in fact is the same with the smoothy region in the channel. 

so i want to make it more smoothy like <<effective first-principles calculation of phonon-assisted photocurrent in large-scale solar cell device>> Figure 1.

i am wondering how to set parameters? more E-dos and K in PLODS option?

Title: Re: how to make the PLDOD more smooth?
Post by: Petr Khomyakov on February 28, 2019, 10:21

Quote from: njuxyh on February 28, 2019, 04:22

i am wondering how to set parameters? more E-dos and K in PLODS option?

Yes, you should definitely increase the number of energy points, e.g., to something like 401 instead of 101 for [-2,2] eV interval, and increase the k-point sampling in the direction (A or B depending on which one is set to be parallel to the MoS2 plane) perpendicular to the transport C-direction, e.g., try 12 k-points for MoS2 - it should be larger than what was used for the corresponding SCF device calculation. 

I note that it is a matter of convergence, so the number given above might need adjustment. Also, there will always be some noise (which depends on the actual device studied) and exponential tails going to the gap regions, since DOS calculation assumes some broadening.