Spectral current density and responsivity scaling for Fourier transform photocurrent spectroscopy

Area of Science:

• Spectroscopy
• Photodetector characterization
• Solid-state physics

Background:

• Fourier transform Photocurrent (FTPC) spectroscopy is a powerful tool for analyzing photodetectors.
• Accurate scaling of FTPC data to physical units like photocurrent spectral density and responsivity is crucial for quantitative analysis.
• Existing methods may lack the precision or applicability for diverse detector types.

Purpose of the Study:

• To propose and experimentally validate a robust methodology for scaling FTPC measurements.
• To extend the scaling to determine detector responsivity (A/W) under specific conditions.
• To demonstrate the technique's effectiveness on different semiconductor materials.

Main Methods:

• Development of a scaling methodology based on interferogram waveform analysis (constant background and interference).
• Formulation of conditions required for accurate data scaling in FTPC.
• Experimental verification using a calibrated Indium Gallium Arsenide (InGaAs) diode and a Silicon Carbide (SiC) interdigital detector.

Main Results:

• Successful scaling of arbitrary units to photocurrent spectral density (A/eV) was achieved.
• The methodology was extended to calculate responsivity (A/W) with narrow-band optical power measurements.
• Identification of impurity-band, interband, and slow mid-gap to conduction band transitions in the SiC detector.

Conclusions:

• The proposed FTPC scaling methodology provides accurate quantitative analysis of photodetector performance.
• This technique enables detailed characterization of electronic transitions in semiconductor devices.
• The method is versatile, applicable to various photodetector types and materials.