This is the README file for the evaluation Java BandProf
distribution of June 2003.

This file is distributed in BandProf.zip, along with some
sample input (*.ht2) files.  The BandProf executable is
found in BandProf.jar, which is an executable JAR file.
To run BandProf, you will need to install the Java 2 Runtime
Environment, version 1.4 or later, on you computer.
Go to http://java.sun.com/j2se/downloads.html to download the
necessary files, and follow the installation instructions for
your computer platform.

On Windows platforms, installing the JRE will associate the
.jar file type with the command:
  javaw.exe -jar 
I have found that this does not work on my systems with
Win98.  A hack that seems to work is to edit the "open"
command so that it reads
  javaw.exe "-jar"

When the file association is properly fixed, clicking on
BandProf.jar should launch the program.

You should see a single window with tabs along the bottom that
switch between the functional windows.  The Design window
first appears.  This is where the textual description of
the device is displayed and edited.  Choose File->Open
to select a device file.  Try pn.ht2, distributed in this
package.  When the design file is displayed, choose
File->Verify.  A graphic window appears which plots the
design graphically.  Return to the Design window and choose
File->Simulate.  The Profile window appears, and the Density
window is also now activated.  The blue dotted lines represent
the quasi-Fermi levels.  Click and drag these lines to change
the applied voltage.  Pausing the pointer over a control will
bring up a tool-tip that explains the function of the control.

BASICS OF THE DESIGN (.ht2) FILES

The file begins with a header that looks like this:

  Title "HT test"
  T = 297.0;
  mesh = 0.001 um;
  Substrate = GaAs;
  Terminals: emitter, base, collector;
  Regions: widegap, narrowgap;

The header information is fairly self-explanatory.  None of these 
is really requred except for the Terminals definition.  It defines the 
names that will be associated with the external terminals.

Next we have the left boundary condition:

  LeftBoundary emitter bulk;

or

  LeftBoundary collector NSchottky = 0.8 eV;

The format is LeftBoundary followed by a terminal name followed 
by the boundary type, ending with a ';'  The boundary type can be 
ohmic (enforces charge neutrality at the boundary), bulk (matches to a 
semi-infinite uniform layer of the adjacent interior composition),
NSchottky, PSchottky, EcPinned, or EvPinned.  The last four require
the specification of a barrier energy.

Next comes the list of layers:

  0.2 um, AlGaAs{Al 0.3} [Ntype = 3.0E19 percm3] emitter;
  0.2 um, [Ptype = 3.0E17 percm3] base;
  0.4 um, [Ntype = 1.0E17 percm3] collector;

First is the thickness, and it is required.  It should be terminated by a ','  
Semiconductors are specified by chemical symbol, with molefractions given inside 
curly braces.  Quaternaries can be specified as AlInGaAs{In 0.48, Al 0.25}
Doping is specified in square brackets.  Finally, the terminal and/or other regions
associated with this layer are named.  A ';' terminates the layer description.

The layer list is followed by the right boundary condition:

  RightBoundary collector ohmic;


The composition and doping levels can be algebraic expressions:

  AlGaAs{Al 0.6* fracRight}
  [Ptype = 1.0E16 percm3, B = 1.2E12 percm2 * gaussNorm (z - zleft - 5 nm, 3nm)]

The variables that one can use in these expressions are:
 z is the coordinate of a point in the layer.
 zleft is the left boundary of the layer.
 zright is  the right boundary of the layer.
 zctr is the center of the layer.
 fracLeft is a variable that decreases from 1 to 0 uniformly through the layer.
 fracRight is a variable that increases from 0 to 1 uniformly through the layer.

USING THE QUANTUM TAB

The Quantum tab lets you find bound-state and resonant energies, and wavefunctions
in the conduction bands of quantum-well structures.  After a valid device simulation
is available, the Quantum tab is enabled.  The top control lets you select which
conduction band to use, the proper choice usually being the Gamma6C band.  Now
push the buton labeled "Capture band profile".  The profile of the selected band
is graphed, and from now on you can regard this as the potential that is input
to the Schroedinger equation solver.  The simulation assumes open-system boundary
conditions and will easily calculate scattering-state wavefunctions.  Click or
drag the mouse on the left-hand side of the Energy graph to create a state incident
from the left with the selected energy.  Similarly, click or drag on the right-hand
side of the graph to launch a state from the right.  Pressing "Find resonances"
will cause the resonant states to be calculated and displayed on the Energy graph.
The states are indicated by a "one-bit grayscale" convention, where the energy is
drawn by lines that extend over those regions where the probability density exceeds
half its peak value.  The resonant wavefunctions can be displayed by clicking on
the energy graph or on the Resonances list widget.  "Plot transmission" produces 
a transmission curve, in which the resonant states have been interpolated so as
to accurately display the peak values of the resonances.

Try the files rtd1.ht2 and sl1.ht2 to exercise the Quantum tab.
In the wavefunction plots, the blue solid line is the real part and the red dashed
line is the imaginary part.


Now, have fun.