Brandon Li’s Semiconductor Simulator Lets You See What’s Really Going On Inside Your Devices
Quantum physicist Brandon Li is looking to dig as deep as possible into the inner workings of the semiconductors that drive modern technology — and has built a simulator that lets anyone draw their own circuit to see how it works.
“I created this simulator because I wanted to get a deeper understanding of how semiconductors work,” Li explains. “It’s been my experience that there’s been a lack of good simulations that demonstrate advanced topics in physics. There certainly exists many educational physics simulations, but they’re all either aimed at lower educational levels, or they are very restricted in how the user can interact with the system. The only examples I’ve seen of simulations that combine advanced topics with a generous amount of interactivity are the physics applets written by Paul Falstad, to whom I’m also grateful for looking over my project and helping to convert it to JavaScript.”
Not your average simulator: a tool written by physicist Brandon Li lets you peer deep into the inner workings of semiconductor devices. (📷: Brandon Li)
While there are no shortages of circuit simulators in the world, Li’s is a little different to most: it simulates on the level of physics rather than functionality, allowing you to visualize exactly what happens when you pass voltage through a resistor, or a bridge rectifier, an LED or even a memory cell — to the point of being able to see the magnetic fields and their interactions.
“I’ve tried to give users many different ways of interacting with the simulation. Circuits can be drawn with just a few clicks of the mouse, allowing users to easily experiment with their own circuits,” Li explains. “There are also many different ways of visualizing the underlying physics that I’ve incorporated into the settings. Each one gives a different perspective on the physics that is happening. At the end of the day, I think the best way to use my program is to just start playing around with it.”
The tool allows for some surprisingly complex devices to be drawn, like this ring oscillator. (📷: Brandon Li)
There are, however, some limitations to the simulation: it doesn’t model electrical breakdown, quantum tunneling, true velocity saturation, or the Hall effect; certain material properties are exaggerated to make their effects more obvious; and metals are modeled as though they were semiconductors with a huge equilibrium carrier concentration. It’s certainly enough, though, to serve as an educational tool.
A browser-based version of the simulator is available on Li’s website; the source code is available on GitHub under the reciprocal GNU General Public License 3, along with downloadable releases that run faster than the web app version — a must for more complicated circuits like a ring oscillator.
