QuantumATK Forum

QuantumATK => General Questions and Answers => Topic started by: tara on January 29, 2015, 13:48

Title: changing basis set
Post by: tara on January 29, 2015, 13:48

Is there any particular preference for using Bassani.Si_Basis set for all silicon p-i-n  device structure as used in
http://quantumwise.com/publications/tutorials/item/828-silicon-p-n-junction     ??

Using  Bassani.Si_Basis  basis set ,it takes much more Slater koster device  calculation  time as compared to  Vogl.Si_Basis basis set .

Secondly, would there be any improvement in convergence at higher bias =0.8v   using  Bassani.Si_Basis  basis set??

Title: Re: changing basis set
Post by: Anders Blom on January 29, 2015, 23:38

The Vogl parameterization is rather rudimentary, it only contains sp3 orbitals, whereas Bassani (or Jancu et al., there are several authors on the paper) created a sp3d5s* model for Si and other semiconductors to make it more accurate. And it is - Vogl is well known to not describe the Delta valley of Si very well at all, and I think you will notice that esp. at high bias.

There have since been published improvements to the Jancu-Bassani models, in particular by Boykin, Klimeck et al., but they mainly adjust details.