Band Gap Estimator(CLI based)

⚠️ Bug present in tauc's module. To be Fixed Soon.

This is a command-line interface (CLI) tool to estimate the band gap energy of a material from UV-Vis spectroscopy data using the Tauc plot method. Platform : Python

Installation

1. Make sure you have Python 3 installed on your system.
2. Install the required Python libraries:

   pip install numpy pandas matplotlib scipy

3. Download the bandgap_estimator.py script and the sample_uvvis.txt file (or your own UV-Vis data file).

Usage

Open your terminal or command prompt and navigate to the directory where you saved the bandgap_estimator.py file.

Basic Usage:

To estimate the band gap from a data file (your_data.txt) assuming a direct band gap:

python bandgap_estimator.py --uvvis your_data.txt

To estimate the band gap assuming an indirect band gap:

python bandgap_estimator.py --uvvis your_data.txt --type indirect

Showing the Tauc Plot:

To display the Tauc plot:

python bandgap_estimator.py --uvvis your_data.txt --plot

Saving the Tauc Plot:

To save the Tauc plot to a file (e.g., tauc_plot.png):

python bandgap_estimator.py --uvvis your_data.txt --plot --output tauc_plot.png

Help:

For more information on the available options, use the --help flag:

python bandgap_estimator.py --help

Input Data Format The UV-Vis data file should be a plain text file with at least two columns separated by whitespace:

Wavelength (nm): The wavelength of the incident light in nanometers. Absorbance: The measured absorbance at the corresponding wavelength. Lines starting with # are treated as comments and are ignored. The file should not have a header row; the first non-comment line should contain the data.

Tauc Plot Method The Tauc plot method is used to determine the optical band gap of semiconductor materials from UV-Vis absorbance or reflectance data. The method involves plotting $(αhν)^n$ versus $hν$, where:

$α$ is the absorption coefficient (proportional to absorbance). $hν$ is the photon energy. $n$ is a factor that depends on the nature of the electronic transition ($n=2$ for direct allowed transitions and $n=1/2$ for indirect allowed transitions). By extrapolating the linear portion of the plot near the absorption edge to the energy axis, the band gap energy can be estimated.

Contributing

Contact me for contributions or any questions.