Defects play an indispensable role in tuning the optical properties of twodimensional materials. Herein, we study the influence of defects on the photoluminescence and resonance Raman spectra of as-grown monolayer (1L) WS 2 . Increasing the density of defects significantly lowers the excitonic binding energy by up to 110 meV. These defect-modified excitonic binding energies in 1L-WS 2 strongly mediate the Raman resonance condition, resulting in unexpected Raman intensity variations in the LA(M), 2LA(M), and A 1 ′(Γ) phonon modes. The sample with the highest density of defects exhibits an almost temperature-independent resonance in different Raman modes at low temperature, whereas the samples with low densities of defects exhibit a clear resonance with decreasing temperature. This study will further increase our understanding of the role of defects in resonance Raman spectroscopy and of the phonon−exciton interaction in 1L-WS 2 .

Micro-/mesoporous SiOC bulk ceramics with high surface area and bimodal pore size distribution were prepared by pyrolysis of polysiloxane in argon atmosphere at 1100°C-1400°C followed by etching in hydrofluoric acid solution. Their thermal behaviors, phase compositions, and microstructures at different nano-SiO 2 filler contents and pyrolysis temperatures were investigated by XRD, SEM, DSC, and BET. The SiO 2 fillers and SiO 2 -rich clusters in the SiOC matrix act as pore-forming sites and can be etched away by HF. At the same time, the SiO 2 filler promotes SiOC phase separation during the pyrolysis. The filler content and pyrolysis temperature have important effects on phase compositions and microstructures of porous SiOC ceramics. The resulting porous SiOC bulk ceramic has a maximum specific surface area of 822.7 m 2 /g and an average pore size of 2.61 nm, and consists of free carbon, silicon carbide, and silicon oxycarbide phases.

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