Observation of band gaps in the gigahertz range and deaf bands in a hypersonic aluminum nitride phononic crystal slab

M. Gorisse , S. Benchabane (1) , G. Teissier (2) , C. Billard (2) , A. Reinhardt (2) , V. Laude (1) , E. Defaÿ (2) , M. Aïd (2)

1 FEMTO-ST - Franche-Comté Électronique Mécanique, Thermique et Optique - Sciences et Technologies (UMR 6174)
2 CEA-LETI - Commissariat à l'énergie atomique et aux énergies alternatives - Laboratoire d'Electronique et de Technologie de l'Information

We report on the observation of elastic waves propagating in a two-dimensional phononic crystal composed of air holes drilled in an aluminum nitride membrane. The theoretical band structure indicates the existence of an acoustic band gap centered around 800 MHz with a relative bandwidth of 6.5% that is confirmed by gigahertz optical images of the surface displacement. Further electrical measurements and computation of the transmission reveal a much wider attenuation band that is explained by the deaf character of certain bands resulting from the orthogonality of their polarization with that of the source.

Mots clés: aluminium compounds; elastic waves; energy gap; III-V semiconductors; phononic crystals; wide band gap semiconductors; Phonon states and bands; normal modes; and phonon dispersion; Semiconductor compounds

Domaines: Acoustique [physics.class-ph]; Acoustique [physics.class-ph]

M. Gorisse, S. Benchabane, G. Teissier, C. Billard, A. Reinhardt, et al.. Observation of band gaps in the gigahertz range and deaf bands in a hypersonic aluminum nitride phononic crystal slab. Applied Physics Letters, 2011, 98, pp.4103. ⟨10.1063/1.3598425⟩. ⟨hal-00639162⟩