The 1D Heterostructure Tool is a program for the design and simulation of 1D heterostructures. It currently implements the effective mass bandstructure model and parameters for materials belonging to GaAs substrate such as GaP, InAs, AlGaAs etc.. The user can also choose to use the semiclassical Fermi-Dirac distribution which can be faster on bigger devices. A friendly GUI has been implemented in order to easily design the heterostructure to be simulated. It is possible to define a new device in a few mouse clicks. The layers can be easily duplicated by means of "Copy and Paste" features and the heterostructure energy band can be visualized before the simulation is launched. A short guide follows:

• Define the heterostructure and click on "Update Visualization" to visualize the entered structure
• Click on "Accept Geometry" and a second tab will appear.
• Modify the simulation numerical parameters (if needed) and click on "Simulate"

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Improvements / modifications in subsequent releases:

• 1.0.1 - The charge calculation for the low temperature case has been corrected.
• 1.0.2 - Plotting of data has been improved and should now be much faster.
• 1.0.3 - Fermi-Dirac distribution implemented.
• 2.0 - Complete overhaul of the structure entry. A friendly Tcl/Tk GUI implemented in which materials can be added to a simple, table-based list from a material list defined in a database. The list is currently limited to materials grown unstrained on a GaAs substrate. The computational kernel is modified to take into account many different materials. There are 2 different HFET designs, as QWIP design and QCL design provided as an input.
• 2.0.1 - The density graph has been improved.
• 2.0.2 - The Material table is now more intuitive. If no layer is selected, the next layer to be filled, when the user clicks on the table, is the first non-empty one. If a layer is selected and the user clicks on the material list then the selected layer is to be filled.
• 2.0.3 - The materials are inserted in the grid with the following prioprity 1 - Clicked Material entry 2 - Selected layer 3 - First non-empty row The Doping Density graph is in logarithmic scale.
• 2.0.4 - Valence band graph has been added. The Tk GUI code makes a difference between alloys and non-alloy materials. No need to specify a "X-mole fraction" value when a material is not an alloy. Graphs are now reflected to be consistent with the direction of x-axis in the Rappture GUI. Hamiltionian constructor has been modified according to Frensley's formulation.
• 2.1.0 - The previous Matlab engine has been totally substituted by the C/C++ engine OMEN3D. More layers have been added. Two checkbuttons have been added for the visualization and calculation of substrate respectively. The layer L01 is now longer in the first default example. Two new graphs have been added, the first one shows the eigenenergies in function of the bias, the second one shows the resonances in function of bias. The resonance finder algorithm has been greatly improved. It is possible now to specify the range of energy where the resonances have to be searched.
• 2.1.1 - The visualization of the substrate (when included) has been improved.
• 2.1.2 - Graph redundancy for "Resonances/Eigenvalues vs bias " has been solved. The Graph "Eigenvalues vs bias" has been improved.
• 2.1.3 - New technologically relevant III-V semiconductor materials have been added. A new material substrate has been added (InAs).

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the following improvements are planned:

• sp3s* tight binding
• multi-band models based on empirical tight binding
• more substrates, with more materials.

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J.M. Sellier	... Tcl/Tk GUI, Rappture GUI (from 1.0.3 on), Matlab code fixes, Core development (from 1.0.3 on), C/C++ code fixes and changes
S. Lee	... Author of C/C++ tight binding simulator engine (OMEN 3-D)
B. Haley	... Material Database developer
G. Klimeck	... Scientific directions, GUI and Algorithm Design
M. Luisier	... Core Matlab simulator up to version 1.0.3
S. Agarwal, X. Wang	... Matlab Code adaptations, initial Rappture GUI (up to 1.0.2)
D. Vasileska	... Scientific directions and testing

MSD FCRP, NCN@Purdue

Researchers should cite this work as follows:

• Jean Michel D Sellier, Sunhee Lee, Gerhard Klimeck, Samarth Agarwal, Xufeng Wang, Dragica Vasileska (2015), "1D Heterostructure Tool," https://nanohub.org/resources/1dhetero. (DOI: 10.4231/D3833MZ0S).

  BibTex | EndNote

1. AQME
2. band structure
3. heterostructures
4. nano devices
5. nanoelectronics
6. Poisson's equation
7. Schroedinger
8. tight-binding