Localized Excitons in Defective Monolayer Germanium Selenide

One-dimensional flat bands in twisted bilayer germanium selenide

Experimental advances in the fabrication and characterization of few-layer materials stacked at a relative twist of small angle have recently shown the emergence of flat energy bands. As a consequence electron interactions become relevant, providing inroads into the physics of strongly correlated two-dimensional systems. Here, we demonstrate by combining large scale ab initio simulations with numerically exact strong correlation approaches that an effective one-dimensional system emerges upon stacking two twisted sheets of GeSe, in marked contrast to all Moiré systems studied so far. This not …

具有高电阻对比度的硒化锗多晶型体间的晶态-晶态相变

Crystalline-to-Crystalline Phase Transition between Germanium Selenide Polymorphs with High Resistance Contrast

本研究探究中等温度整体退火或局部激光诱导加热引发的GeSe晶态多晶型体间相变，发现γ-GeSe可转变为α-GeSe且界面特性独特，Ge空位聚集为关键机制，两者电阻对比度达10^7，突显其在电子应用中的潜力。

A simulation of the cluster structures in Ge-Se vitreous chalcogenide semiconductors

A structure of germanium selenide glasses is simulated by the featured clusters built from the tetrahedral GeSe4 units up to the clusters with six germanium atoms (Ge6Se16H4 and Ge6Se16H8). Quantum chemical calculations at the DFT level with effective core potentials for Ge and Se atoms for the clusters of different composition reveal their relative stability and optical properties.

Outstanding thermoelectric performance predicted for out-of-plane p-doped GeSe

The record-breaking thermoelectric performance of tin selenide (SnSe) has motivated the investigation of analogue compounds with the same structure. A promising candidate that emerged recently is germanium selenide (GeSe). Here, using extensive first-principles calculations of the hole-phonon and hole-impurity scattering, we investigate the thermoelectric transport properties of the orthorhombic phase of p-doped GeSe. We predict outstanding thermoelectric performance for GeSe over a broad range of temperatures due to its high Seebeck coefficients, extremely low Lorenz numbers, ultralow total t…

Direct ab initio MD simulation of silver ion diffusion in chalcogenide glasses

In this paper, we present new models of germanium selenide chalcogenide glasses heavily doped with silver. The models were readily obtained with ab initio molecular dynamics and their structure agrees closely with diffraction measurements. Thermal molecular dynamics simulation reveals the dynamics of Ag+ ions and the existence of trapping centers as conjectured in other theory work. We show that first principles simulation is a powerful tool to reveal the motion of ions in glass.

Si和Ge中的多型量子阱：二维六方夹杂物对电子能带结构的影响

Polytypic Quantum Wells in Si and Ge: Impact of 2D Hexagonal Inclusions on Electronic Band Structure

本研究探索了硅和锗中由层错形成的二维六方夹杂物作为量子阱的电子能带结构特性，发现其表现出可调的直接带隙并形成Type-I量子阱，为通过扩展缺陷工程化半导体光电性质及先进器件应用提供了新途径。