Electrical characterization of semiconductor materials

A method for characterizing electronic properties of a semiconductor sample, the method comprising:

• illuminating the surface of the semiconductor sample with a continuous background illumination having a predefined intensity and photon energy higher than an energy gap of the semiconductor;
• illuminating the surface of the semiconductor sample with a continuous probing illumination that has a modulated intensity, the probing illumination being superimposed over the background illumination to yield a measurable alternating current photoconductance (ac-photoconductance) in the semiconductor sample, the measurable ac-photoconductance having real and imaginary components;
• setting the modulated intensity of the probing illumination such that the measurable ac-photoconductance in the semiconductor sample becomes linearly dependent on the modulated intensity of the probing illumination;
• and
• measuring the real and imaginary components of the ac-photoconductance in the semiconductor sample;
• and
• determining a steady-state carrier recombination lifetime for the semiconductor sample under background illumination using the measured real and imaginary components of the ac-photo conductance.