iradina
ion range and damage in nanostructures
iradina logo
3D Monte Carlo Simulation of Ion Beam Irradiation of Nanostructures
iradina is a computer program for the simulation of ion beam irradiation of nanostructures. iradina simulates the transport of energetic ions through solid matter by calculating binary collisions and employing a Monte Carlo (MC) transport algorithm. Here are some of the key features of iradina:
3D targets
The target in iradina is defined by a three-dimensional rectangular grid, allowing almost arbitrary target geometries. This is in contrast to other popular programs like for example TRIM, where simulation is limited to flat / bulk targets. iradina was originally developed to calculate the distribution of implanted ions and of implantation defects in semiconductor nanowires.
Free software
iradina is free software. It is licensed under the GPLExternal link. It is open source and you can adapt the program to your needs, as long as you respect the GPL. iradina is written in plain c and can be used on different platforms (with one restriction: IEEE 754 conform bit representation of single precision floats is required - but don't worry, most of today's systems do conform). iradina has been tested thoroughly on windows and linux systems.
Optimization
iradina is optimized for speed. Table-lookup functions are used instead of calculating electronic stopping and scattering angles upon each collision. The lookup-functions with a very fast indexing mechanism are taken from the free corteoExternal link program, which is a program to calculate accurate ion beam analysis spectra by a full binary collision simulation of the ion transport processes.
Flexibility
iradina is non-interactive: it can run in the background, do work for other programs and can be run from scripts for example to perform huge numbers of different simulations automatically. There is a graphical user interface (iraUI) which is independent from iradina itself. iraUI is interactive and helps the user by automatically generating the input files for running iradina. Furthermore, iraUI includes a plotting tool to analyze the simulation results.
What
iradina
can do:
- simulate ion beam irradiation of solid targets with ion energies from a few eV to a several MeV
- represent 3d target geometries within a rectangular grid of several million cells
- output various results: distribution of implanted ions, recoils, different types of defects, ion trajectories, recoil trajectories, final ion positions, vectors and energy of transmitted ions, distribution of deposited energy
- calculate sputtering yields in nanostructures, global and local (per cell)
What
iradina
cannot do:
- simulate irradiation with electrons, quarks, photons, multi-atom clusters, or any other particle not being a single atom with an atom number from 1 to 92
- dynamically change the target composition due to irradiation (...work on this is in progress...). If you need that, look for TRI3DYNExternal link.
- simulate ion beam deposition with small ion energies (below a few 10 eV)
- simulate channeling effects or any other effect related to the crystallinity of the target.
- simulate dynamic annealing
- temperature dependent effects (T=0 at all times)
- ... many other things that would be interesting ...
Warning:
Results from iradina have been verified by experiments on various examples (see below). However, in some cases iradina may produce very unrealistic results having nothing to do with physical reality! You should never trust the results from any physics simulation code! When using results from simulations you should at least basically understand how the simulation works and make sure that all assumptions made in the code about the physical system are fulfilled.
The scientific background of iradina is described hereExternal link.
Download
You need two things in order to run iradina:
- Corteo database files
- Iradina executable file
The database files can be downloaded from here, from the Corteo websiteExternal link or can be build from scratch using corteo. The database files must be placed in a subdirectory called "data" within the directory of the iradina executable. Read the manual for more details.
Windows users can download the precompiled iradina executables. For all other operating systems, download the source code and compile it (it is written in c and can be compiled with the gcc.) For details, read the manual.
Iradina is written in plain c and is released under the GNU general public licenseExternal link.
Download:
https://sourceforge.net/projects/iradina/External link
User Interface:
iradina itself has no user interface at all, which allows it to do background work for other programs. However, a graphical user interface exists for Windows users (.net framework 3.5 required). Technically, it is independent from iradina and it does not include iradina. It prepares all neccessary input files and starts iradina, and it can be used to analyze results generated by iradina. The user interface currently is freeware but not open source.
The graphical user interface iraUI can be downloaded here.zip, 497 kb · de
Application examples
This is a list of selected projects and tasks where iradina has been used to simulate ion beam irradiation. If you would like your example to appear on this page, please let us know.
| Application | Description | Publication |
|
Ion beam doping of nanowires |
iradina simulations are used to determine the distribution of implanted ions and of implantation defects in semiconductor nanowires. Conventional bulk simulations cannot be used to obtain accurate results. |
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Sputtering effects in ion beam doping of nanowires |
The enhanced sputtering of nanowires during ion beam doping is investigated experimentally and compared to calculations performed with iradina. |
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Ion beam induced bending and alignment of nanowires |
Ion bean induced bending and alignment of nanowires can be induced by inhomogeneous defect distributions. In order to understand the bending mechanisms, detailed defect distributions need to be known. They can be obtained using iradina. |
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Ion implantation profiles in MacPSi solar cells |
Macroporous silicon (MacPSi) is a promising material for solar cell absorber layers due to its outstanding light trapping properties. In this work, ion implantation was applied to selectively dope the outer surfaces of a free-standing MacPSi layer to fabricate a solar cell. Iradina was used to understand the influence of the pore geometry on the distribution of the implanted dopant atoms. |
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Damage and ion profiles in ion beam irradiated Bi nanowires |
Modification of the structure and morphology of Bi nanowires. For low fluences, the main effect was a slight roughening of the originally smooth surface and the appearance of a damaged zone at the wire edges. After a medium exposure depressions are seen, giving the wires a “wavy” morphology. At the largest fluence tested, the thickest nanowires present an amorphized structure, while the thinner wires collapse into large nanoparticles. The observed morphologic modifications are discussed considering sputtering and radiation induced surface diffusion effects. |
Bi nanowires modified by 400 keV and 1 MeV Au ions |
| Distributions of defects in irradiated nanowire solar cells in comparison to planar structures |
The authors demonstrate that III–V nanowire-array solar cells have dramatically superior radiation performance relative to planar solar cell designs and show this for multiple cell geometries and materials, including GaAs and InP. Nanowire cells exhibit damage thresholds ranging from ∼10–40 times higher than planar control solar cells when subjected to irradiation by 100–350 keV protons and 1 MeV electrons. Using iradina simulations, they show that this improvement is due in part to a reduction in the displacement density within the wires arising from their nanoscale dimensions. |
Radiation Tolerant Nanowire Array Solar Cells |