Wippermann Stefan, Vörös Márton, Gali Adam, Gygi Francois, Zimanyi Gergely T, Galli Giulia
Interface Chemistry and Surface Engineering Department, Max-Planck-Institute for Iron Research GmbH, Max-Planck-Straße 1, 40237 Düsseldorf, Germany and Chemistry Department, University of California, Davis, California 95616, USA and Physics Department, University of California, Davis, California 95616, USA.
Chemistry Department, University of California, Davis, California 95616, USA and Physics Department, University of California, Davis, California 95616, USA.
Phys Rev Lett. 2014 Mar 14;112(10):106801. doi: 10.1103/PhysRevLett.112.106801. Epub 2014 Mar 11.
We propose that embedding silicon nanoparticles (NP) into amorphous, nonstoichiometric ZnS leads to promising nanocomposites for solar energy conversion. Using ab initio molecular dynamics simulations we show that, upon high temperature amorphization of the host chalcogenide, sulfur atoms are drawn to the NP surface. We find that the sulfur content may be engineered to form a type II heterojunction, with complementary charge transport channels for electrons and holes, and that sulfur capping is beneficial to lower the nanoparticle gap, with respect to that of NPs embedded in oxide matrices. Our analysis is conducted using density functional theory with local and hybrid functionals and many body perturbation theory at the GW level.
我们提出，将硅纳米颗粒（NP）嵌入非晶态、非化学计量比的硫化锌中可得到有望用于太阳能转换的纳米复合材料。通过从头算分子动力学模拟，我们表明，在主体硫族化物高温非晶化时，硫原子会被吸引到NP表面。我们发现，可以通过控制硫含量来形成II型异质结，为电子和空穴提供互补的电荷传输通道，并且相对于嵌入氧化物基质中的NP，硫封端有利于降低纳米颗粒的能隙。我们的分析使用了密度泛函理论，包括局域泛函和杂化泛函，以及GW水平的多体微扰理论。
