High-frequency acoustic wave detection in Schottky diodes: theory consideration

In this paper the theory of high-frequency acoustic signal detection by Schottky diodes is presented. Physically, the detection was found to be due to the quasi-static screening of the potential perturbation caused by the acoustic strain by charge carriers. The total charge required for screening changes with the value of strain at the edge of the semiconductor depletion region and metal-semiconductor interface giving rise to displacement current. The magnitude and frequency dependence of the electrical signals are analyzed for both piezoelectric and deformation potential coupling mechanisms. The obtained results are in good agreement with the recent experimental observations and suggest feasibility of high-frequency (up to terahertz band) acoustic wave detection provided that proper electrical measuring scheme is available.