We propose and experimentally verify a methodology to scale arbitrary units to photocurrent spectral density (A/eV) in Fourier transform Photocurrent (FTPC) spectroscopy. We also propose the FTPC scaling to responsivity (A/W), provided a narrow-band optical power measurement is available.
The methodology is based on an interferogram waveform consisting of a constant background and interference contribution. We also formulate conditions that have to be met for correct scaling.
We experimentally demonstrate the technique on a calibrated InGaAs diode and weak responsivity, long response time SiC interdigital detector. We identify a series of impurity-band and interband transitions in the SiC detector and slow mid-gap to conduction band transitions.