Experimental Observation of Electron-Phonon Interaction in Semiconductor on Solidly Mounted Thin-Film Lithium Niobate

We report the experimental demonstration of electron-phonon interaction in a semiconductor on solidly mounted thin-film lithium niobate (LiNbO
3
). The prototype is based on a shear horizontal surface acoustic wave (SH-SAW) acoustic delay line platform in thin-film LiNbO
3
-on-sapphire, featuring simultaneously low-loss and high electromechanical coupling (K
²
). A thin film silicon (Si) layer is transferred and patterned on the top of the LiNbO
3
-on-sapphire stack. The testbed at 1.15 GHz shows strong transmission tunability under different DC bias voltages, namely 12.8 dB insertion loss (IL) contrast for 30 V static DC bias. The passband also demonstrates different bandwidths (BW) for positive and negative bias. Upon further development, this platform will enable efficient tunable acoustoelectric devices for integrated acoustic signal processing.