u have to use the keyword called user.material where u can just give ur material name and in another line u have to use  user.default material which should be related to ur material and in that u can define the other properties like effective density of states , this u can calculate if you know the effective mass of electron and holes, then mentioned the band gap, electron affinity , permittivity etc. These values u can get directly from the papers. I hope this information is enough for u to get a start... 

You can define your new material on the material section. Then, you should define the parameters of your material. This is an example of defining graphene in ATLAS:

material material=Graphene user.group=conductor user.default=ITO mun=10000 mup=10000 permittivity=25 index.file=graphene.nk

Thanks for your respond Sara, i tried your method, but an error appear : " No default material speciefed for user material "InGaBi, setting Silicon as default" and this because the New material InGaBi dont exist in ATLAS default materials, so ATLS will reconize it as Silicon by default (P.S: my Silvaco atlas version is 2005"

You should define your material in the region section like this: "region num=33 user.material=Graphene x.min=0 x.max=2 y.min=0 y.max=0.0015"

You should write "user.material" for InGaBi not "material".  Did you write like this?

yeah i write user.material=InGaBi in the region statement

in the material statement i write user.group=semiconductor user.default=PPV permitivity=... eg300=... and all the parameter of this material, but always the same warning appear  No default material speciefed for user material "InGaBi, setting Silicon as default" can u try to write this in ur silvaco version and see if the warning appear or no please? i have silvaco version 2005 and how abour u? do u think that the version of silvaco is the problem?

take an example of solar cell modeling and change the material by InGaBi

any body can help me to get 2013 version of SILVACO ATLAS please

I don't think it was about the version of your software, because I use the old version too but I do not see this warning. If you want, you can send the relevant part of your code. I will check it for you.

Good luck

Ok Sara, i send one part of my code

Please Sara, can you try to excute this flag : "2dxy.schro" in material statement if it works correctly and reconized by your SILVACO version?

wait ur respond

Hello, there is a new about the program?

Dear Beghdaoui,

Sorry for my late. I was a bit busy during the past few days. By the way, I saw the file which you sent, but, unfortunately, I can't find the file that you define the new material.

Hello sara, i have a little problems with silvaco atlas program, im trying to simulate an InAsN/GaN quantum dots structure, as u know the InAsN is ternary material and it varied with x composition, but when i change x in the region statement,  i obtain the same results in the output!! realy i dont know where is the problem

Dear Beghdaoui 

InAsN is ternary material which is not present in Silvaco. so u see the variation of x for the default material that the new material(InAsN) is based on.

u have to use the keyword called user.material where u can just give ur material name and in another line u have to use  user.default material which should be related to ur material and in that u can define the other properties like effective density of states , this u can calculate if you know the effective mass of electron and holes, then mentioned the band gap, electron affinity , permittivity etc. These values u can get directly from the papers. I hope this information is enough for u to get a start... 

This paper may help

http://iopscience.iop.org/article/10.1088/1757-899X/211/1/012024/meta