Acoustoelectric Study of Interface Trapping Defects in GaAs Epitaxial Strucrures

A new acousto-electrical method making use of transient transverse acoustoelectric voltage (TAV) to study solid state structures is reported. This voltage arises after a surface acoustic wave (SAW) generating the signal is switched off. Related measurements consist in detecting the shape of transient voltage and its spectral and temperature dependence. Both theory and experiment show that this method is an effective tool to characterize trapping centers in the bulk as well as at surfaces or interfaces of epitaxial semiconductor structures.