Observation of acoustoelectric effect in micromachined lamb wave delay lines with AlGaN/GaN heterostructure

We report on the first time observation of acoustoelectric (AE) effect from the interaction of acoustic Lamb waves and two-dimensional electron gas (2DEG) in an AlGaN/GaN heterostructure. Micro-fabricated Lamb wave delay lines are used to launch and guide travelling acoustic waves through the 2DEG region, resulting in a DC current flow between two ohmic contacts positioned on the delay line. The Lamb wave delay line shows much better acoustic transmission efficiency than the conventional surface acoustic wave (SAW) counterpart. The dependence of AE current on RF power and frequency is also verified.