The optical properties of 2D semiconductors made of transition metal dichalcogenide monolayers, such as Mo${X}_{2}$ and W${X}_{2}$ ($X$=S, Se), are dominated by excitons. The light emission yield for optoelectronics applications depends on whether the electron-hole transitions are optically allowed (bright) or forbidden (dark). No direct evidence of the energetic ordering of these exciton states is currently available. The authors here solve the Bethe-Salpeter equation with $G\phantom{\rule{0}{0ex}}W$ wave functions in order to determine the sign and amplitude of the splitting between bright and dark exciton states in the entire Mo${X}_{2}$ and W${X}_{2}$ monolayer family. They also evaluate the influence of pin-orbit coupling on the optical spectra and clearly demonstrate the strong impact of the intravalley Coulomb exchange term on the dark-bright exciton splitting, an important ingredient for engineering optoelectronics and spintronics applications.

Splitting between bright and dark excitons in transition metal dichalcogenide monolayers

Effect of welding processes and conditions on the microstructure, mechanical properties and corrosion resistance of duplex stainless steel weldments—A review

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Splitting between Bright and Dark Excitons in Transition Metal Dichalcogenide Monolayers

Influence of microstructure and elemental partitioning on pitting corrosion resistance of duplex stainless steel welding joints

https://cyberleninka.org/article/n/1477609.pdf

Weldability, machinability and surfacing of commercial duplex stainless steel AISI2205 for marine applications – A recent review

Evolution of microstructure and corrosion behavior in 2205 duplex stainless steel GTA-welding joint

Effect of sandblasting and subsequent acid pickling and passivation on the microstructure and corrosion behavior of 316L stainless steel

The molybdenum–iron–boron–chromium claddings with different Mo/B atomic ratios were produced on Q235 steel using argon arc welding. The microstructure and crystalline phases were studied by optical microscopy, scanning electron microscopy and XRD. In addition, the formation mechanism of hard phase was investigated by thermodynamic calculations and phase diagrams. The results showed that the claddings were composed of the Mo2FeB2, M3B2 (M: Mo, Fe and Cr) hard phases and σ-FeMoCr solid solution. In addition, calculated results revealed that the M3B2, MB and σ-FeMoCr were successively precipitated from the melting pool. Moreover, the maximum microhardness value of the cladding was about 1600 HV0.5. Wearing test indicated that claddings of lower Mo/B ratios have better wear resistance.

Microstructure and mechanical properties of molybdenum–iron–boron–chromium cladding using argon arc welding

The joint of dissimilar metals between Mo2FeB2-based cermets and 316L stainless steel was welded by gas tungsten arc welding with no fillers. The weldability was investigated by plate rigid restraint cracking test and transverse rupture strength was measured by the three-point bending test. Microstructure of the weld joint was studied with scanning electron microscope, energy-dispersive spectrometer, X-ray diffractometer and differential scanning calorimeter, etc. Corrosion behavior was investigated by the potentiodynamic polarization test. Results revealed that weld solidification cracking susceptibility existed in the fusion zone. Coarse irregular complex ternary boride phase (M3B2) and hypoeutectic microstructure were formed in weld metal (WM). In heat affected zone (HAZ), a small number of M3B2 grains dissolved into the γ-Fe based binder, with growth and coalescence of the remaining M3B2 grains. Microhardness of HAZ increased slightly and WM presented the highest microhardness in the whole joint. Besides, potentiodynamic polarization test showed that WM had a better corrosion resistance than Mo2FeB2-based cermets, which can be attributed to the higher Cr content and relatively homogenous Mo distribution.

Characterization of weldability, microstructure, and corrosion resistance of dissimilar welded joint between Mo 2 FeB 2 -based cermets and 316L stainless steel

Junsheng Sun

Papers

Evolution of microstructure and corrosion behavior in 2205 duplex stainless steel GTA-welding joint

Effect of sandblasting and subsequent acid pickling and passivation on the microstructure and corrosion behavior of 316L stainless steel

Microstructure and mechanical properties of molybdenum–iron–boron–chromium cladding using argon arc welding

Characterization of weldability, microstructure, and corrosion resistance of dissimilar welded joint between Mo 2 FeB 2 -based cermets and 316L stainless steel