Published February 3, 2026 | Version 1.9
Software Open

SOLEY - A simulation package for solar cells

Authors/Creators

Description

The landing page of SOLEY can be found here


Important note: The Linux and MacOS versions have not been thoroughly tested. The windows version normally ok on all machines, but very high resolution screens may experience scaling issues. 

New in 1.9:

  • Terrible bug fix! In 1.8, moving or removing a layer would mess up the layer labelling and the optical and device modelling was all over the place. THis was fixed.
  • Photon recycling was implemented, which justifies going to version 1.9
  • Several bug fixes and a few QoL changes

New in 1.8:

  • HTML-based GUI
  • BIfacial solar cells
  • Various bug fixes
  • Probably new bugs...
  • In 1.81: MacOS version is now a .dmg and the IEC 60904-1-2 standard for bifacial modelling

SOLEY – Solar Cell Simulation Package

SOLEY is a scientific-grade simulation software for modelling the optical and electrical performance of photvoltaic solar cells. It does not intend to replace existing packages which use the drift diffusion model, but rather to complement those by offering an alternative approach.

🟠 Optical Simulation Capabilities

  • Transfer Matrix Method for multilayer optical calculations
  • Bruggeman effective medium approximation for composite layers (could sometimes be buggy as it messes the layer indexing)
  • Direct and diffuse illumination with angle and polarisation control (TE, TM, unpolarised)
  • Generation profile computation
  • Parallel wavelength processing for faster simulations. Not always faster due to overheads unfortunately 🗿

🔵 Device Physics & Electrical Modelling

  • Extended detailed balance framework
  • Photoluminescence and Electroluminescence modelling
  • Multi-junction support (2T, 4T/6T etc. configurations)
  • Recombination mechanisms: SRH, radiative, and Auger
  • Custom defect input: trap density, capture cross-sections, bulk and interface defects etc. The whole enchilada.
  • Series and shunt resistance effects
  • Dynamic carrier injection variation (through a very innaccurate slider)
  • Possibility to bypass the optical caluclation and use a step absorption, as in the SQ limit. If non radiative recombination are set to 0 and resistances are inexistent, you get the SQ limit.
  • External SQ calculator

🟢 Analysis & Visualisation

  • J–V curve generation (dark and illuminated)
  • PL, PL(V) and EL curve generation
  • EQE calculations to come in a future update
  • Bandgap extraction from absorbance spectra, but always double check please!
  • Plotting of R, T, and internal absorption
  • Batch parameter sweeps and thickness optimisation

🟣 Data Handling & Export

  • Export optical profiles, generation data, J–V curves…
  • Save/load full simulation states as .soley files
  • CSV export for external tools

Future updates will add EQE (using thermodynamic equations, the goal is not to redo what SCAPS already does so well), other built-in recombination pathways, intermediate band solar cells, hot carrier solar cells etc. Just be patient with me pretty please.

Files

SOLEY_Manual_1_9.pdf

Files (276.1 MB)

Name Size Download all
md5:8ae6dd8f1f034bce038589c5e5e68f6f
115.0 MB Download
md5:b858090b5e74f8d1af1ed0a5fdfbe15f
67.1 MB Download
md5:42a37fd6acb9576c10be574a837afdd3
93.6 MB Download
md5:b62ecaa2498eaa96cbeaa8a7fdcc1452
365.4 kB Preview Download

Additional details

Software

Repository URL
https://zacharie-li-kao.github.io/SOLEY-PV/
Programming language
Python