相关论文: Direct Bandgap Emission from Hexagonal Ge and SiGe…
We present ab initio calculations of the electronic and optical properties of hexagonal SiGe alloys in the lonsdaleite structure. Lattice constants and electronic band structures in excellent agreement with experiment are obtained using…
Silicon's inherently indirect bandgap severely limits its radiative efficiency, posing a fundamental challenge to the development of practical silicon-based light sources. While strategies such as nanoscale confinement of electrons and…
We report electrical measurements on hexagonal silicon-germanium (hex-SiGe), a group IV alloy with direct bandgap. Electrical contacts are formed by metal alloying and doping is achieved using ion implantation. The metastable hex-SiGe phase…
Hexagonal SiGe is a promising material for combining electronic and photonic technologies. In this work, the energetic, structural, elastic and electronic properties of the hexagonal polytypes (2$H$, 4$H$ and 6$H$) of silicon and germanium…
High-quality defect-free lonsdaleite Si and Ge can now be grown on hexagonal nanowire substrates. These hexagonal phases of group-IV semiconductors have been predicted to exhibit improved electronic and optical properties for optoelectronic…
Utilizations of silicon-based luminescent devices are restricted by the indirect-gap nature of diamond silicon. In this study, the high-throughput method is employed to expedite discoveries of direct-gap silicon crystals. The machine…
The emergence of hexagonal Ge (2H-Ge) as a candidate direct-gap group-IV semiconductor for Si photonics mandates rigorous understanding of its optoelectronic properties. Theoretical predictions of a "pseudo-direct" band gap, characterized…
The lack of straightforward epitaxial integration of useful telecom lasers on silicon remains the major bottleneck for bringing optical interconnect technology down to the on-chip level. Crystalline silicon itself, an indirect…
Diamond silicon (Si) is the leading material in current solar cell market. However, diamond Si is an indirect band gap semiconductor with a large energy difference (2.4 eV) between the direct gap and the indirect gap, which makes it an…
A true monolithic infrared photonics platform is within reach if strain and bandgap energy can be independently engineered in SiGeSn semiconductors. Herein, we investigate the structural and optoelectronic properties of a 1.5 {\mu}m-thick…
Hexagonal group IV materials like silicon and germanium are expected to display remarkable optoelectronic properties for future development of photonic technologies. However, the fabrication of hexagonal group IV semiconductors within the…
Silicon indirect bandgap fundamentally limits its ability to emit light, hindering the development of silicon-based light sources. Here, we explore a conceptually new solution to this long-standing challenge. We demonstrate ultrabroadband…
The development of semiconductor electronics is shortly reviewed, beginning with the development of germanium devices (band gap $E_g=0.66$ eV) after world war II. Quickly a tendency to alternative materials with wider band gap became…
As one of the most important semiconductors, silicon (Si) has been used to fabricate electronic devices, waveguides, detectors, and solar cells etc. However, its indirect bandgap hinders the use of Si for making good emitters1. For…
Silicon is the most popular material used in electronic devices. However, its poor optical properties owing to its indirect band gap nature limit its usage in optoelectronic devices. Here we present the discovery of super-stable…
Unlike cubic GeSn, which requires a high Sn concentration to undergo an indirect-to-direct bandgap transition, lonsdaleite (2H) germanium is an intrinsic direct-gap semiconductor. We employ first-principles density functional theory to…
Here, the structural, electronic and optical properties of the GaP1-xSbx/Si tandem materials association are determined in view of its use for solar water splitting applications. The GaPSb crystalline layer is grown on Si by Molecular Beam…
Pushing dopant concentrations beyond the solubility limit in semiconductors -- a process known as hyperdoping -- has been demonstrated as an effective strategy for inducing superconductivity in cubic-diamond Si and SiGe materials.…
Despite their electronic dominance, cubic diamond structured Si and Ge, are optoelectronically deficient. Recent work indicates, however, that a volume-expanded hexagonal Ge modification can exhibit intensely sought, superior optoelectronic…
Crystal defects, traditionally viewed as detrimental, are now being explored for quantum technology applications. This study focuses on stacking faults in silicon and germanium, forming hexagonal inclusions within the cubic crystal and…