Controlling the heat transport and thermal conductivity through a material is of prime importance for thermoelectric applications. Phononic crystals, which are a nanostructured array of specially designed pores, can suppress heat transportation owing to the phonon wave interference, resulting in bandgap formation in their band structure. To control heat phonon propagation in thermoelectric devices, phononic crystals with a bandgap in the THz regime are desirable. In this study, we carried out simulation on snowflake shaped phononic crystal and obtained several phononic bandgaps in the THz regime, with the highest being at ≈2 THz. The phononic bandgap position and the width of the bandgap were found to be tunable by varying the neck-length of the snowflake structure. A unique bandgap map computed by varying the neck-length continuously provides enormous amounts of information as to the size and position of the phononic bandgap for various pore dimensions. We have also carried out transmission spectrum analysis and found good agreement with the band structure calculations. The pressure map visualized at various frequencies validates the effectiveness of snowflake shaped nano-pores in suppressing the phonons partially or completely, depending on the transmission probabilities.

中文翻译：

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用于热声子工程的石墨烯声子晶体的设计。

对于热电应用而言，控制通过材料的热传递和热导率至关重要。声子晶体是经过特殊设计的孔的纳米结构阵列，可由于声子波干扰而抑制热传输，从而在其能带结构中形成带隙。为了控制热声子在热电设备中的传播，需要在THz范围内具有带隙的声子晶体。在这项研究中，我们对雪花形的声子晶体进行了仿真，并在THz范围内获得了几个声带隙，最高为≈2THz。发现声子带隙的位置和带隙的宽度可通过改变雪花结构的颈长来调节。通过连续改变颈部长度计算出的独特带隙图可提供大量有关各种孔尺寸的声子带隙的大小和位置的信息。我们还进行了传输频谱分析，发现与频带结构计算有很好的一致性。在各种频率下可视化的压力图验证了雪花形纳米孔在部分或完全抑制声子方面的有效性，具体取决于传输概率。