论文标题
超级晶格导热率和高热电性能在Janus Monolayer HFSSE的室温附近
Ultralow lattice thermal conductivity and high thermoelectric performance near room temperature of Janus monolayer HfSSe
论文作者
论文摘要
自过去几年以来，二维过渡金属DI-Chalcogenide（TMDC）在高温下表现出巨大的潜力，这是由于其合适的带隙，低维度和奇妙的电导率和晶状体导热性的奇妙组合，因此在高温下具有高质量的热电材料。在这里，借助密度功能理论和Boltzmann传输方程，进行了两维单层HFS 2，HFSE 2，HFSE 2，HFSE 2，HFSE 2，HFSE 2，HFSE HFSSE的第一原理计算。所有三个结构的热力学稳定性已从声子分散曲线中得到证实。在300K，400K和500K处计算了诸如Seebeck系数，功率因数和电导率之类的热电参数。与非常流行的TMDC（例如MOS 2和WS 2）相比，单层HFS 2，HFSE 2和HFSSE JANUS单层中的晶格导热率非常低。在Janus Monolayer HFSSE中，在室温下，晶格导热率的超低值低于单层HFS 2和HFSE 2的超值电导率，因为HFSSE中的HFS 2和HFSE 2的超低型HFS 2和HFSE 2。 Janus单层HFSSE中的这种超低晶格导热率导致非常高的热电图，值得在室温下接近1的值。通过构建HFS 2和HFSE 2的Janus单层，热电性能显着增强。我们的理论调查预测，Janus Monolayer HFSSE可以成为制造下一代可穿戴热电发电机以将人体热量转化为电力的革命性候选者。
Two-dimensional transition metal di-chalcogenides (TMDCs) have shown great potential as good quality thermoelectric materials at high temperature since past few years due to their suitable band gap tunabilty, low dimensionality and fantastic combination of electrical conductivity and lattice thermal conductivity. Here, a first principles calculations of electronic and thermoelectric performance of two dimensional monolayer HfS 2 , HfSe 2 and their Janus monolayer HfSSe has been performed with the help of density functional theory and Boltzmann transport equation. Thermodynamical stability of all three structures has been confirmed from phonon dispersion curves. The thermoelectric parameters such as Seebeck coefficient, power factor and electrical conductivity have been calculated at 300K, 400K and 500K. The lattice thermal conductivity at room temperature has been found very low in monolayer HfS 2 , HfSe 2 and HfSSe Janus monolayer as compared to very popular TMDCs such as MoS 2 and WS 2 . An ultralow value of lattice thermal conductivity of the value of 0.36 W/mK at room temperature in Janus monolayer HfSSe has been found which is lower than that of monolayer HfS 2 and HfSe 2 because of the very low group velocity and short phonon lifetime in HfSSe. This ultralow lattice thermal conductivity in Janus monolayer HfSSe results a very high thermoelectric figure of merit close to the value of 1 at room temperature. By constructing the Janus monolayer of HfS 2 and HfSe 2 the thermoelectric performances significantly enhanced. Our theoretical investigation predicts that Janus monolayer HfSSe can be a revolutionary candidate for the fabrication of next generation wearable thermoelectric power generator to convert human body heat into electricity.
