声速对硅基氮化铝复合声子晶体带隙影响

该文基于布喇格散射机理,采用有限元仿真技术重点研究材料声速对二维AlN/B/Si复合声子结构体带隙特性的影响。首先以Mo作为B层,逐次分析AlN、AlN/Mo、AlN/Mo/Si出现最大带隙宽度时,AlN、Mo、Si各层厚度的最优值;然后分别选取具有声速梯度的材料作为B层,研究B材料声速对复合声子晶体带隙宽度变化率的影响。结果表明,当B层与Si、AlN的声速差值小于3 000 m/s时,B层厚度的变化引起复合声子晶体带隙宽度变化率低于25%,而B层与Si、AlN的声速差值越大,改变B层厚度会造成带隙宽度变化率越大,最高可达100%。

Influence of Sound Velocity on Band Gap of Silicon Based Aluminum Nitride Composite PhononicCrystals

In this paper, based on the Bragg scattering mechanism, the influence of material sound velocity on the band gap characteristics of two dimensional AlN/B/Si composite phononic crystal is studied by using the finite element numerical simulation technology. Firstly, the optimum thickness of each layer of AlN, Mo, Si are analyzed successively by using Mo as the B layer when the maximum band gap width of AlN, AlN/Mo and AlN/Mo/Si occurs. Then the material with sound velocity gradient is selected as B layer to study the effect of sound velocity on the band gap width change rate of composite phononic crystals. The results show that when the difference of sound velocity between B layer and Si and AlN is less than 3 000 m/s, the change rate of band gap width of composite phononic crystals is less than 25% due to the change of B layer thickness. The bigger the difference of sound velocity between B layer and Si, AlN, the bigger the change rate of band gap width will be caused by changing the thickness of B layer, up to 100%.