Solar cell simulation using extended detailed balance and Transfer Matrix Method optical calculations.
SOLEY is a simulation platform for researchers and engineers working on photovoltaic device optimisation. Unlike traditional drift-diffusion simulators, SOLEY implements an extended detailed balance framework combined with rigorous Transfer Matrix Method (TMM) optical calculations, offering a complementary approach to existing tools like SCAPS-1D or PC1D.
Built on detailed balance principles ensuring physical accuracy
Native support for tandem and multi-terminal configurations
Customisable recombination pathways
TMM calculations with generation profile export
Integrated PL/EL for material characterization
Ideality factor and differential resistance vs voltage
Rear-side absorption with albedo and angular TMM
Rau optical reciprocity for effective J0_rad calculation
Advanced optical modeling for enhanced absorption
Quick parameter screening and optimization
See SOLEY in action with these interface examples:
Choose your platform below. SOLEY now requires installation. Example files are located in the installation directory (Program Files/SOLEY/ for Windows).
All releases are archived on Zenodo with DOI versioning.
File → Open → Select "perovskite_silicon_tandem.soley"
Click "Calculate TMM" to compute absorption profiles
Navigate to "Device Physics" tab and review recombination settings
Tools → J-V Characteristics → Select illumination conditions
File → Export → Choose CSV or PNG format
1. Define layer stack (materials + thicknesses) 2. Assign optical constants (n, k data) 3. Run TMM calculation 4. Set absorber parameters (Eg, defects, etc.) 5. Choose illumination (spectrum, angle, intensity) 6. Run electrical model (J-V, Generation, PL, etc.) 7. Analyze and export results
single_junction_silicon.soley - Basic c-Si deviceperovskite_silicon_tandem.soley - 2T tandem cellCZTS.soley - Sulphur KesteriteCZTSe.soley - Selenium KesteriteConsult the full User Manual (PDF) for detailed tutorials and parameter explanations.
SOLEY implements the Fresnel-based TMM for stratified media:
Reference: Jimenez et al., Sol. Mat. 251, 112109 (2023), DOI: 10.1016/j.solmat.2022.112109
The device physics engine solves:
J(V) = Jph - J0_rad·[exp(qV/kT) - 1]
- J0_SRH·[exp(qV/nkT) - 1]
- JAuger(V)
- V/Rsh
- J·Rs
Key advantages:
Reference: Jehl Li-Kao, Solar RRL (2025), DOI: 10.1002/solr.202500345
SOLEY translates microscopic trap parameters into macroscopic J₀ using the formulation from Scaffidi et al.:
Bulk recombination: J₀₀_bulk = π·kB·T·√(ε·Nc·Nv/(2·q·Vbi·Ndop))·vth·σn·Nt Interface recombination: J₀₀_interface = q·Sp·Ndop·[(Nc_adj·Nv)/(Ndop_adj·Ndop)]^(1-θ) Final J₀_SRH: J₀_SRH = (J₀₀_bulk + J₀₀_interface)·exp(-Ea/(n·kB·T))
Reference: Scaffidi, R. et al. Newton 1(8), 100198 (2025). DOI: 10.1016/j.newton.2025.100198
Thermodynamic equations with improved collection probabilities
Intermediate band solar cells modelling
Non-thermal carrier distributions
Version history and changelog for SOLEY releases.
Release Date: February 2026
Major Updates:
Release Date: January 2026
Minor Update:
Release Date: January 2026
Major Updates:
Release Date: December 10th, 2025
Major Updates:
Release Date: October 30th, 2025
Key Features:
Release Date: September 15th, 2025
Key Features:
If you use SOLEY in your research, please cite:
Jehl Li-Kao, Z. "SOLEY: a package for optical and extended detailed balance model for photovoltaic device simulation." Solar RRL (2025). DOI: 10.1002/solr.202500345
@article{jehl2025soley,
author = {Zacharie Jehl Li-Kao},
title = {SOLEY: a package for optical and extended
detailed balance model for photovoltaic
device simulation},
journal = {Solar RRL},
year = {2025},
doi = {10.1002/solr.202500345}
}
SOLEY is distributed for academic use only. Commercial use requires explicit written permission from the author.
By downloading and using SOLEY, you agree to:
Get in touch for questions, bug reports, feature requests, or collaboration opportunities.
Use subject prefixes:
[SOLEY Bug] - Bug reports
[SOLEY Feature] - Feature requests
[SOLEY Collaboration] - Research collaboration
Zacharie Jehl Li-Kao
Universitat Politècnica de Catalunya (UPC)
Barcelona, Spain