A Technique for Photoelectric and Photodielectric Effect Measurements at Microwave Frequencies

This paper describes a novel technique, based on the use of a microwave bridge, for the determination of very small changes in the phase and attenuation constants of semiconductor materials. Using this technique, the photoelectric and photodielectric effects in a semiconductor sample under external illumination can be determined. The room-temperature photodielectric effect Δϵ
^'
_r
and the photoelectric effect Δϵ
^"
_r
of silicon and germanium single-crystal samples were measured in the X-band region in the presence of monochromatic illumination in the range from 0.8 to 2.0 , μm. It was found that the variations of Δϵ
^'
_r
and Δϵ
^"
_r
with respect to the wavelength of the illumination were similar, with a maximum response at about 1.05 μm for silicon and at 1.75 μm for germanium.