Acoustoelectric interaction in semiconductors

Experimental observations are reported of high-frequency currents associated with thin photoconducting cadmium sulphide platelets having flat and parallel faces. They appear under conditions when `round-trip gain' due to acousto-electric amplification is achieved. They are correlated with departures from Ohm's law. The results are confined to conditions under which a linear theory is believed applicable. The linear theory is outlined and comparison is made with a variety of experimental observations. Semiquantitative agreement is obtained.

https://iopscience.iop.org/article/10.1088/0022-3719/2/1/324/pdf

High-frequency acoustoelectric currents and departures from Ohm's law in thin platelets of CdS I. Linear behaviour

A review is given of a variety of physical effects in piezoelectric semiconductors originating in the relative strong coupling between the electronic and sound wave systems. Among the topics discussed are sound amplification, non-electronic losses, effects of free carrier trapping, and a number of strong non-linear effects as current saturation, current oscillations, and traveling high field and flux domains. A short discussion of some recent non-linear theories is also included.

Acoustoelectric Effects in Piezoelectric Semiconductors with main Emphasis on CdS and ZnO

It was pointed out in 1960 that metals and semiconductors can support low frequency electromagnetic excitations in the presence of a magnetic field. We now feel that it is an appropriate time to discuss some of the progress made, over the last decade, in understanding and using this novel phenomenon. Naturally the field has grown quite rapidly and it would clearly be a Herculean task to review every aspect of it in other than a superficial manner. We have therefore chosen to discuss only semiconductors and semi-metals. This choice is dictated to us partly by the fact that magneto-plasma effects in metals have been reviewed from time to time but mainly by the fact that magneto-plasma effects in semiconductors have never been previously reviewed. Of course the term ‘magneto-plasma’ covers a great deal of activity so we have decided to choose a theme which links the beginnings of the subject to the present day. This theme is that of helicon and Alfven wave propagation. We have produced a background ...

D. L. White

Papers

Active CdS Ultrasonic Oscillator