Novel concepts for GaAs/LiNbO3 layered systems and their device applications

Thin semiconductor quantum well structures fused onto LiNbO3 substrates usi ng the epitaxial lift-off (ELO) technology offer the possibility of control ling the surface acoustic wave (SAW) velocity via field effect. The tunabil ity of the canductivity in the InGaAs quantum well results in a great chang e in SAW velocity, in general, accompanied by an attenuation. We show that an additional lateral modulation of the sheet conductivity reduces the SAW attenuation significantly, enhancing device performance. At high SAW intens ity, the bunching of electrons in the SAW potential also leads to a strong reduction of attenuation. These effects open new possibilities for voltage- controlled SAW devices. We demonstrate a novel, wireless, passive voltage s ensor, which can be read out from a remote location.