# Simulation results for Simulation of Photonic Crystal Enhanced Ge-on-Si Single Photon Avalanche Diode Performance for Operation at 1550 nm

This dataset contains TCAD and optical simulations for analysis of Ge-on-Si photonic crystal enhanced single photon avalanche diodes, optimised for 1550 nm wavelengths. Further data and/or help with these files is available from the corresponding author upon reasonable request.

**Corresponding Author:** Ross W. Millar (Ross.Millar@Glasgow.ac.uk)

## TCAD Data

TCAD data is generated using Synopsys Sentaurus S-2021.06-SP1. The subset of simulation results required to recreate findings has been included with the fields:
- Electric Field
- Conduction Band Energy
- Valence Band Energy
- Electron Quasi-Fermi Energy
- Hole Quasi-Fermi Energy

Data for a range of relevant reverse bias steps is included around breakdown for each device structure used in the findings. Each step takes the form:
- `contacts.json`
- `boundary`*
	- `regions.csv`: List of material regions and interfaces
	- `vertices.csv`
	- `elements.csv`
	- `<regionName>_vertexIndices.csv` (One file per region)
	- `<regionName>_elementIndices.csv` (One file per region)
- `grid`
	- `regions.csv`
	- `vertices.csv`
	- `elements.csv`
	- `faces.csv`*
	- `<regionName>_vertexIndices.csv` (One file per region)
	- `<regionName>_elementIndices.csv` (One file per region)
- `datasets`
	- `datasets.csv`
	- `electricField.csv`
	- `conductionBandEnergy.csv`
	- `valenceBandEnergy.csv`
	- `eQuasiFermiEnergy.csv`
	- `hQuasiFermiEnergy.csv`

*3D simulation only

The `grid` data contains the mesh, while the `boundary` provides the outline in the case of a 3D mesh. Meshes are defined by a list of vertices as well as a list of elements. Elements define edges, triangles, and tetrahedron that make up a mesh. These are specified by a number to define the element type, followed by the corresponding vertex indices:
- 0: Point (1 vertex)
- 1: Line (2 vertices)
- 2: Triangle (3 vertices)
- 5: Tetrahedron (4 vertices)
- 10: Polyhedron (3xN vertices for N faces)

## Optical Data

Optical data is generated using Lumerical FDTD 3D Electromagnetic Simulator. 

- `Optimisation`
	- `GePC`
		- `abs_<pitch>nm_<radius>nm_<etchDepth>nm.csv`
	- `aSiPC`
		- `abs_<pitch>nm_<radius>nm_<etchDepth>nm.csv`
	- `Reference`
		- `abs_<thickness>nm.csv`

	Absorption spectra is given for varying PC pitch, radius, and etch depth for both the Ge-etched (`GePC`) and aSi designs (`aSiPC`). Data is also given for the ARC design optimisation as the `Reference` dataset.

- `Absorption`
	- `grid_<design>.json`
	- `abs_<design>`
		- `slice_<zIndex>.json` (One for each z value)

	For each design the simulation mesh is given in `grid_<design>.json`, with x, y, z, and wavelengths. Absorption data is split into z slices within `abs_<design>`, and only contains that at 1550 nm. Each slice contains the values in the xy plane.

## Loading data
Data requires a custom written loader (not provided). All files use either `json` or `csv`.