Effect of strain on exciton dynamics in monolayer WS2

The exciton dynamics in a WS2 monolayer with strain are studied by transient absorption measurements.We measure the differential transmission signal from monolayer WS2 as a function of the probe wavelength at different levels of strain applied to the sample.The differential transmission spectrum has a positive maximum value at about 614 nm and shows no significant strain dependence.By time-resolving the differential transmission signal,we find that the strain has a minimal effect on the exciton formation process.However,the exciton lifetime is significantly reduced by strain.These results provide useful information for applications of WS2 in flexible electronic and optoelectronic devices where strain is inevitable.

Chemical vapor deposition growth of crystal monolayer SnS2 with NaCl-assistant

As an important member of the two-dimensional layers of metal dichalcogenides family, the two-dimensional(2 D)group IV metal chalcogenides(GIVMCs) have been attracting intensive attention. However, the growth of monolayer tin disulfide(SnS2) remains a great challenge contrasted to transition metal dichalcogenides, which have been studied quite maturely. Till date, there have been scant reports on the growth of large-scale and large-size monolayer SnS2. Here, we successfully synthesized monolayer SnS2 crystal on SiO2/Si substrates via NaCl-assisted CVD and the edge can be as long as 80 μm. Optical microscope, Raman spectroscopy, x-ray diffraction, atomic force microscopy(AFM), and energydispersion x-ray(EDX) were performed respectively to investigate the morphology, crystallographic structure, and optical property of the 2 D SnS2 nanosheets. In addition, we discussed the growing mechanism of the NaCl-assisted CVD method.

Procollagen C-proteinase enhancer 1 promotes physiologic retinal angiogenesis via regulating the process of collagen

AIM:To investigate the role of procollagen C-proteinase enhancer 1(PCPE1)in retinal angiogenesis and relevant mechanisms.METHODS:The Pcolce1-knockout(KO)mice were used to explore the effect of PCPE1 on retinal angiogenesis in vivo.Pcolce1 si RNA were designed,cell count kit 8(CCK8)assays and tube formation assays were performed to investigate the cell proliferation and tube formation abilities of retinal microvascular endothelial cells(h RMECs)in vitro.Mouse embryo fibroblasts(MEF)cells were isolated and cultured to analyze the effect of PCPE1 on enhancing procollagen cleavage.RESULTS:In vivo studies showed that the retinal vascular density of Pcolce1-/-mice was significantly lower than that of the control group.Furthermore,silencing of Pcolce1 inhibited cell proliferation and tube formation abilities of h RMECs in vitro.Additionally,much more procollagen was found in Pcolce1-/-MEF cells,compared to wild type MEF cells.CONCLUSION:PCPE1 may promote physiological retinal angiogenesis by regulating the processing of collagen,which may provide a potential therapeutic target of retinal vascular disease.