Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy ( IF 4.4 ) Pub Date : 2020-09-12 , DOI: 10.1016/j.saa.2020.118939 Maria I.A. de Oliveira , Roberto Rivelino , Fernando de Brito Mota , Anelia Kakanakova-Georgieva , Gueorgui K. Gueorguiev
We investigate theoretically the electronic and optical absorption properties of two sub-classes of oligosilanes: (i) Si(CH3)4, Si4(CH3)8, and Si8(CH3)8 that contain Si dot, ring and cage, respectively, and exhibit typical SiC and SiSi bonds; and (ii) persilastaffanes Si7H6(CH3)6 and Si12H6(CH3)12, which contain extended delocalized σ-electrons in SiSi bonds over three-dimensional Si frameworks. Our modeling is performed within the GW approach up to the partially self-consistent GW0 approximation, which is more adequate for reliably predicting the optical band gaps of materials. We examine how the optical properties of these organosilicon compounds depend on their size, geometric features, and Si/C composition. Our results indicate that the present methodology offers a viable way of describing the optical excitations of tailored functional Si-C-based clusters and molecular optical tags with potential use as efficient light absorbers/emitters in molecular optical devices.
中文翻译:
准粒子自洽GW计算包含σ电子离域的有机硅化合物的光学性质
我们从理论上研究了低聚硅烷的两个子类别的电子和光学吸收特性:(i)Si(CH 3)4,Si 4(CH 3)8和Si 8(CH 3)8包含Si点,环和分别保持笼形并显示出典型的Si C和Si Si键; (ii)全硅黄烷烃Si 7 H 6(CH 3)6和Si 12 H 6(CH 3)12,它们在Si中包含扩展的离域σ电子硅在三维硅框架上键合。我们的模型是在GW方法内执行的,直到部分自洽的GW 0近似值为止,这对于可靠地预测材料的光学带隙更为合适。我们研究了这些有机硅化合物的光学性质如何取决于其尺寸,几何特征和Si / C组成。我们的结果表明,本方法学提供了一种可行的方法来描述定制的基于功能Si-C的团簇和分子光学标签的光学激发,并有可能在分子光学器件中用作有效的光吸收剂/发射体。