A high electron mobility phonotransistor

Acoustoelectric devices convert acoustic energy to electrical energy and vice versa. Devices working at much higher acoustic frequencies than those currently available have potential scientific and technological applications, for example, as detectors in phononics experiments and as transducers in bulk acoustic wave filters at terahertz (THz) frequencies. Here we demonstrated an active acoustoelectronic device based on a GaAs heterostructure: an acoustically gated transistor or phonotransistor. Instead of being controlled in the conventional manner by an electrical signal applied to a metallic or semiconductor gate as in a high electron mobility transistor (HEMT), the drain-source current was controlled by a bulk sub-THz acoustic wave passing through the channel in a direction perpendicular to the current flow.