arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 2004.13955cond-mat.mtrl-sci
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二维XI $_2$(X=Sn,Si)的光电和热电性质:第一性原理研究

Impressive optoelectronic and thermoelectric properties of two-dimensional XI$_2$ (X=Sn, Si): a first principle study

Atanu Betal, Jayanta Bera, Satyajit Sahu

摘要:

二维金属卤化物由于其电子学和光电学性质而受到越来越多的关注。近年来,由于金属卤化物单层膜具有超低的晶格电导率、高的Seebeck系数和品质因数,研究者们对金属卤化物单层膜的热电性能产生了浓厚的兴趣。本文利用密度泛函理论和Boltzmann输运方程研究了XI $_2$(X=Sn和Si)单分子膜的热电和光电性质。通过原子位置弛豫优化了结构参数。SnI $_2$和SiI $_2$单分子膜均具有优异的热电和光学性能。对于SnI $_2$,观察到2.06 eV的间接带隙,并且在4.68 eV处发现吸收峰。为此,已计算出600K下p型掺杂的最高ZT值为0.84。类似地,对于SiI $_2$,观察到1.63 eV的相对低的间接带隙,并且在4.86 eV处获得吸收峰。计算得到SiI $_2$在600 K时的ZT乘积为0.87。这两种晶体具有高的吸收率和ZT值,表明它们可以作为光电和热电器件的有希望的候选者。

英文摘要:

Two-dimensional (2D) metal halides have received more attention because of their electronic and optoelectronic properties. Recently, researchers are interested to investigate the thermoelectric properties of metal halide monolayers because of their ultralow lattice conductivity, high Seebeck coefficient and figure of merit. Here, we have investigated thermoelectric and optoelectronic properties of XI$_2$ (X=Sn and Si) monolayers with the help of density functional theory and Boltzmann transport equation. The structural parameters have been optimized with relaxation of atomic positions. Excellent thermoelectric and optical properties have been obtained for both SnI$_2$ and SiI$_2$ monolayers. For SnI$_2$ an indirect bandgap of 2.06 eV was observed and the absorption peak was found at 4.68 eV. For this the highest ZT value of 0.84 for p-type doping at 600K has been calculated. Similarly, for SiI$_2$ a comparatively low indirect bandgap of 1.63 eV was observed, and the absorption peak was obtained at 4.86 eV. The calculated ZT product for SiI$_2$ was 0.87 at 600K. Both the crystals having high absorbance and ZT value suggest that they can be promising candidates for optoelectronic and thermoelectric devices.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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