About

The Author

A little background on who wrote these tools, and where they came from.

I have spent many years as a Principal Research Fellow and Associate Professor at a research and teaching university in the UK, working in the field of solid-state semiconductor physics.

The applications on this site are connected only in that I wrote them in the course of that work. They are practical tools that grew out of research and teaching, rather than parts of a single product — each has its own origin and purpose.

CFTool

CFTool began as a way to demonstrate and facilitate non-linear curve fitting for undergraduate and postgraduate students. It has since matured into a quick, intuitive application that is regularly used to produce publication-quality work.

Several visiting schools have used CFTool during school-outreach and student-experience visits, and have gone on to express an interest in using it in their own teaching — which is why I have chosen to make it freeware.

EpiSolve

EpiSolve has a longer history. For years I relied on the widely-cited 1D Poisson solver written by Professor Greg Snider (University of Notre Dame), but it had no graphical interface or output plotting, which made it slow to work with. I wrote a GUI with built-in plotting around it, and the combination proved very quick for generating layer structures — I came to use it regularly in my own lab work and teaching.

Later I wanted that same capability but with the freedom to add modules for specific problems, so I set about writing my own Poisson–Schrödinger solver in Python, driven by the same interface. EpiSolve is the result: fast, easy generation of layer structures, the solution of confined states via the Schrödinger equation, and a CV module for capacitance sweeps — very useful for producing band diagrams on the fly.

While EpiSolve derives conceptually from Professor Snider’s original tool, it shares no code with it — any overlap is limited to a few material parameters that may have come from his materials file, and that I used his program to validate my own results.