Thank you very much Farid Djahli (sir)!

Density of states of semiconductors increase with effective mass increase and effective mass increase does result in band gap increase. Effective mass needs to be changed substantially to moderately increase band gap and substantially increase density of states as it is proportional to m^1,5 if 3D density of states is considered. See the attached papers.

Sincerely,

Dr. Nabil Shovon Ashraf.

Thank you very much Dr. Nabil Shovon Ashraf (sir)!

Density of states is also related to the occupied electron states and hence it should be high when band gap is zero as it does in the case of metals. In semiconductor, density states is usually small at the Fermi level as less occupied electron states (due to s, p hybridization). This concept takes me in a confusion that band gap increases in TB-mBJ potential calculation (as expected ) as well as density of states. Doesn't it mean that the occupied electron states at the Fermi level increase and it cannot be accounted by PBE functional? Thanks in advance

Your work is with regard to perovskite semiconductor material and I have attached a paper which does a detailed bandstructure E-k diagram based works. Most of my work is with semiconductor materials and if you specifically let me know whether metal or transition metal element and if its alloy you are considering, you can let me know the metal or its alloy and I will try to give you papers on that if you don't have them already.

Sincerely,

Dr. Nabil Shovon Ashraf.

You initially reported work with perovskite semiconductor material. I have attached a paper on this that should address some of your queries like DOS and effective mass relation. If your question is with regard to metal, then if you give the name of the metal, transition or rare earth metal and its alloy, I can look for quality analysis that you may find useful for your work.

Sincerely,

Dr. Nabil Shovon Ashraf.

Dear Nabil Shovon Ashraf (Sir),

My question was actually on the perovskite semiconductor!

Thank you very much!

Best regards

Enamul Haque

See this paper. This paper is more specific for your queries even though the material may be different than that of your research.

Sincerely,

Dr. Nabil Shovon Ashraf.

Thank you very much Dr. Nabil Shovon Ashraf (sir)!

I understand now!

Thanks all

Your last answer tells me that the papers I attached gave you the clues for resolution of your question. Getting proper material for answering your question was not easy for me and I read these papers before deciding whether the articles are in line with your question. Would you please recommend my answers to your question put here. It will go a long way to prove that I have expertise in this field specially device physics and transport analysis of nanoscale structures.

Sincerely,

Dr. Nabil Shovon Ashraf.

Dear Botan Jawdat Abdullah ,

Thank you for your response! I agree with you. Please, can you explain why it should be true for perovskite semiconductor? Is this confinement true for other types of semiconducting materials? Thanks in advance!