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Author Topic: Bandstructure of GaN  (Read 3959 times)

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Offline kesh

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Bandstructure of GaN
« on: September 23, 2013, 20:52 »
Hi!
I am trying to simulate the bandstructure of GaN and I know it has a direct band gap of about 3.4eV but the results I'm getting from the simulation shows an indirect band gap. Do I need to do something extra before simulating it?

Thanks
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Offline Nordland

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Re: Bandstructure of GaN
« Reply #1 on: September 23, 2013, 21:13 »
Are you doing a DFT-LDA calculation?
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Offline kesh

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Re: Bandstructure of GaN
« Reply #2 on: September 24, 2013, 15:08 »
Yes I am doing a DFT-LDA calculation
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Offline Nordland

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Re: Bandstructure of GaN
« Reply #3 on: September 24, 2013, 21:17 »
So if your question goes to why the band gap is not the correct value, I have this link http://www.iop.kiev.ua/~yakovkin/My_pdf/Exchange_gap.pdf for you. It is more or less - a fundamental properties that
the band gap is not well described in LDA. There are method for compensate for this like LDA+U or MGGA, but it is an intrinsic property of LDA that it gives too small band gaps.
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Offline kesh

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Re: Bandstructure of GaN
« Reply #4 on: September 24, 2013, 21:32 »
Thank you! :)
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