Compared with most previously predicted and synthesized silicon phases, these allotropes exhibit lower energy, which are only 0.042, 0.037, 0.056, and 0.120?eV/atom higher than that of diamond-Si. These silicon allotropes are direct or quasi-direct semiconductors with band gaps in the range of ...
Direct and quasi-direct band gap silicon allotropes with remarkable stability In our present work, five previously proposed sp3carbon crystals were suggested as silicon allotropes and their stabilities, electronic and optical propert... C He,C Zhang,L Jin,... - 《Physical Chemistry Chemical ...
To evaluate the sunlight absorption abilities of a direct band gap material, the imaginary parts of the dielectric constant of oP36- Si2He, mC12-Si2He and three silicon allotropes (oC24-Si, tP6-Si, and mC8-Si) were calculated by HSE06 functional, compared with that of CD-Si, as ...
Although the band structure using the HSE06 functional is similar to that obtained at the PBE level, the band gap is increased to 0.61 eV. This value is much smaller than that of all the predicted direct band gap silicon allotropes at the HSE06 level. In addition, we note that the...
This feature has remained difficult to achieve in the case of silicon, an indirect gap semiconductor, because interband transitions there require phonons and recombination centers (Castellanos-Gomez et al., 2012). One of the interesting recent applications of 2D MoS2 nanocrystals is the transistor (...
To date, four major material types have been investigated, being cadmium compounds, silicon, metal oxide nanoparticles and low band gap nanoparticles. Currently, Cadmium Sulfide (CdS) quantum dots represent the state of the art, yielding a PCE of greater than 4%. This review compares the ...
The ability of some chemical elements or allotropes of the elements, to exist in two or more distinct forms in the same physical state is known as allotropy. Different structural alterations of an element are known as allotropes: The way the elements atoms are linked together is different. ...
Silicon is a preferred material in solar cells,and most of silicon allotropes have an indirect band gap.Therefore,it is important to find new direct band gap silicon.In the present work,a new direct band gap silicon allotrope of o-Si32 is discovered.The elastic constants,elastic anisotropy,...
In this paper, using silicon triangles as the building block, we propose a new silicon allotrope with a direct band gap of 0.61 eV, which is dynamically, thermally and mechanically stable. Symmetry group analysis further suggests that dipole transition at the direct band gap is allowed. In...
Importantly Mica band gap tuned from 7.5 to 0.5 eV with semimetallic nature when layer number is reduced to atomically thin [3]. In this chapter, we will discuss structure property of nanosheets mainly graphene, black phosphorus, MoS2, MXenes, LDH, and phyllosilicates....