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Modeling the Coupling Between Surface Acoustic Waves in Lithium Niobate and Carrier Dynamics in GaN Thin Films for Optoelectronic Modulation

Posted 3 mar 2026, 01:30 GMT-5 Semiconductor Devices, MEMS & Piezoelectric Devices, Modeling Workflow Version 6.3 0 Replies

姿雅郭

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Hello everyone,

I am currently working on simulating a device involving a Gallium Nitride (GaN) thin film bonded onto a Lithium Niobate (LiNbO₃) substrate. My core objective is to investigate how the Surface Acoustic Waves (SAWs) generated in the LiNbO₃ substrate can modulate the carrier dynamics (e.g., electron-hole pairs, photocurrent) within the bonded GaN film.

I have successfully studied individual physics using the COMSOL Application Library:

The optoelectronic effects in the GaN film, based on the "Gallium Arsenide pin Diode" example.

The frequency response of SAWs, based on the "SAW Gas Sensor" example.

My main challenge is coupling these two physics together in a single model. Specifically, I need to simulate how the piezoelectric effect in LiNbO₃ (induced by an RF signal) generates a SAW, and subsequently, how the mechanical strain and/or piezoelectric field from this SAW affects the electronic transport and optical generation/recombination processes in the GaN layer.

I am unsure about the correct Multiphysics interface to use. Should I couple Solid Mechanics with Semiconductor physics using a predefined coupling, or is a more manual approach required (e.g., using the strain from the SAW as an input for deformation potential or polarization changes in the Semiconductor interface)?

Any guidance on setting up the physics coupling, selecting the appropriate study type (e.g., frequency-domain perturbation for small signals?), or relevant example models would be greatly appreciated.

Thank you for your time and help.

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