Modeling terahertz magneto-optical spectroscopic ellipsometry with conductive sheet approximation for semiconductor...

Area of Science:

• Condensed matter physics
• Materials science
• Terahertz spectroscopy

Background:

• Terahertz magneto-optical ellipsometry is a powerful technique for probing electronic properties of materials.
• Analyzing anisotropic semiconductor thin films requires accurate models to interpret complex optical responses.
• Existing models may not be suitable for very thin films where thickness is much smaller than the wavelength.

Purpose of the Study:

• To present a simplified electromagnetic model for analyzing reflection coefficients of anisotropic semiconductor thin films.
• To validate the model's applicability in terahertz magneto-optical ellipsometry for thin films.
• To demonstrate a non-invasive method for extracting sheet conductivity spectra.

Main Methods:

• Derivation of the model from electromagnetic boundary conditions.
• Application of terahertz time-domain spectroscopic ellipsometry.
• Experimental validation using doped gallium arsenide (GaAs) thin films under an external magnetic field.

Main Results:

• The simplified model is valid for thin films where thickness is much smaller than the wavelength.
• The model accurately reproduces the magneto-optical response of doped GaAs thin films.
• Direct extraction of sheet conductivity spectra was achieved.

Conclusions:

• The developed simplified model provides an effective means for analyzing anisotropic semiconductor thin films.
• This approach offers a non-invasive and accurate method for material characterization using terahertz magneto-optical ellipsometry.
• The technique has broad applicability for various thin-film materials.