Recently, the team of the Quantum Information Technology Center of the Chongqing Institute of Green Intelligent Technology of the Chinese Academy of Sciences has made the latest progress in the IVAVIB large-area single atomic layer material preparation, energy band structure determination, and device test analysis and research represented by GeSe.

At present, nearly 100 kinds of two-dimensional materials have been discovered, including the binary compounds composed of the fourth main group, the third and fifth main groups, metal chalcogenides, and complex oxides. These findings not only broke the long-standing claim that two-dimensional crystals could not stably exist in nature, but also exhibited many novel physical and electronic properties such as half-integer, fractional and fractal quantum Hall effects, and high migration. Rate, energy band structure change. The IVAVIB single-crystal two-dimensional material MX (M = Ge, Sn; X = S, Se) has been subjected to extremely high stability, environmental friendliness, abundant reserves, and similarity in structure and performance to the black phosphene. extensive attention. Based on the first-principles method, the calculation of the energy band structure of MX, the critical layer thickness from indirect band gap to direct band gap, and the theoretical prediction of piezoelectric performance based on its C2v symmetric structure have been reported. However, due to its brittleness, it is difficult for this type of material to be directly prepared by a physical tearing method to obtain a single atomic layer material. With chemical synthesis, it is also difficult to obtain a large area of ​​monoatomic layers (greater than 1 micron). Therefore, the research on IVAVIB single-crystal two-dimensional materials still remains at the stage of theoretical prediction.

In MX, GeSe is theoretically considered to be the only material with a direct bandgap, and the spectral range prediction of this material covers almost the entire spectrum of sunlight, which makes it huge in quantum optics, photodetection, photovoltaics, electricity, and other fields. Application potential. Based on this, the Chongqing Institute of Quantum Information Technology Center team found that the use of silicon dioxide monocrystalline silicon surface insulation effect and laser thinning method, can be in a certain laser power density continuously thinned GeSe layer thickness, until single Atomic layer. The thinning mechanism is that the laser generates high heat in the GeSe surface layer. Due to the layered nature of the GeSe material, it is difficult to conduct heat out in time, resulting in continuous thinning of the layer thickness. When the GeSe layer thickness is thinned to the monoatomic layer, the entire SiO2/Si can be regarded as a heat sink and cannot continue to be thinned. Using this method, the team for the first time fabricated a GeSe single-atom layer material with a size of more than 100 microns. Based on fluorescence spectroscopy, Raman spectroscopy and other methods, the atom and energy band structure of the GeSe monoatomic layer was studied and based on the first-principle principle. The method theory confirms the reliability of the experimental results. Experimental and theoretical calculations show that the fluorescence spectrum of GeSe monoatomic layer is very wide, and 8 fluorescence peaks are found from the visible to near-infrared bands. The transition from indirect band gap to direct band gap occurs in the third layer. In addition, the team experimentally fabricated transistors based on GeSe bulk materials and two-dimensional materials. The IV and photo-reaction properties indicate that the photosensitivity of two-dimensional materials is 3.3 times that of the corresponding bulk materials, and the photoreactivity of two-dimensional material devices It is also far superior to the corresponding bulk material device.

Related research results were published on Advanced Functional Materials. The study was funded by major projects in Chongqing's foundational frontiers, the “Western Light” Western Academy’s Class A program of the Chinese Academy of Sciences, and the National Natural Science Foundation of China.

Kitchen Faucet

Kitchen faucet

A kitchen faucet is one of the most frequently used devices in your home. Our modern kitchen faucets offer an exciting mix of innovation, style and functionality to meet the demands of every household. We offer many types of Kitchen Sink faucets to choose from, including pull-down kitchen faucets, pull-out kitchen faucets, one, three hole faucets, faucets with multi-layer brushed nickel finishes and PVD finish ect .

Kitchen Faucet,American Standard Kitchen Faucets,Touchless Faucet,Brass Kitchen Tap

Jiangmen MEIAO Kitchen And Bathroom Co., Ltd. , https://www.meiaosink.com