home *** CD-ROM | disk | FTP | other *** search
- Newsgroups: sci.materials
- Path: sparky!uunet!mcsun!news.funet.fi!funic!nntp.hut.fi!elfys4.hut.fi!ktas
- From: ktas@finsun.csc.fi (Kimmo Taskinen)
- Subject: Re: Heterojunction bandstructure calculations
- Message-ID: <ktas.1@finsun.csc.fi>
- Sender: usenet@nntp.hut.fi (Usenet pseudouser id)
- Nntp-Posting-Host: elfys4.hut.fi
- Organization: Electron Physics Laboratory, Helsinki University of Technology
- References: <1992Nov4.192627@IASTATE.EDU> <83220@ut-emx.uucp>
- Date: Tue, 10 Nov 1992 07:37:53 GMT
- Lines: 73
-
- In article <83220@ut-emx.uucp> vcm@ccwf.cc.utexas.edu (V. Chandramouli) writes:
-
- >In article <1992Nov5.081229.2190@nntp.hut.fi> you write:
- >>
- >> Howdy,
- >>
- >> Does anybody know where to get simulation programs to do bandstructure
- >>and carrier density calculations for hetrostructures, preferably for ones
- >>containing several stacked quantum wells ? We have one written here in HUT,
- >>but it only handles one half-well, not a set of complete wells ( a super-
- >>lattice) or eg. two interacting wells.
- >>
- >> Thanks,
- >> Mikko Kiviranta
- >>
-
- >I am interested in your model -- can I have a copy of it ?
-
- >For stacked quantum wells, I am aware of several papers in the
- >literature that describes how to calculate the band structure.
- >If you are interested in heterostructure device simulation you should
- >consult the software from Purdue University (Mark Lundstrom's group)
- >called PUPHS. This program can (I think) calculate carrier
- >densities in a heterostructure. If you need more information on
- >the contact e-mail address and bibliography please send me an
- >e-mail (mouli@emx.cc.utexas.edu).
-
- >Chandramouli. mouli@emx.cc.utexas.edu
- >---------------------------------------------------------------------
- >Microelectronics Research Center in the University of Texas at Austin
- >---------------------------------------------------------------------
-
- If Mikko is talking about a simulation program I wrote (or anyway), I must
- say that itcan calculate structures of several heterojunctions. But in order
- to do thatyou have to recompile the program for each specific structure (and
- convergence is not obvious).
-
- Other facts about my program:
-
- - It is an interactive simulation program for the conventional HEMT- or
- MODFET-structures (AlGaAs). You get the sheet carrier concentration in the
- channel as a function of the gate voltage.
-
- - It solves the Schroedinger's and the Poisson's equations self-
- consistently using the finite difference method described in 'Numerical
- Recipes in C'.
-
- - Initial guess is very important for convergence. When program is
- executed it fetches the initial guess from a file. Later the result of
- previous calculation is always used as an initial guess.
-
- - Setting parameters are: gate voltage, thickness and donor density of doped
- AlGaAs layer, thickness of the spacer (undoped AlGaAs) layer,
- acceptor density in substrate (GaAs) and temperature.
-
- - Only the two lowest subbands are considered.
-
- - Program menus are unfortunately written in finnish.
-
-
- If you are still interested, email me. I can translate the menus in english
- if you wish.
-
-
- ---------------------------------
- | Kimmo Taskinen|
- | ktaskine@finsun.csc.fi|
- | Electron Physics Laboratory|
- |Helsinki University of Technology|
- | Otakaari 7A|
- | SF-02150 Espoo|
- | FINLAND|
- ---------------------------------
-