Inhalational delivery of antibiotics to the CF airway can be optimized when the sputum barrier is concomitantly addressed. Co-delivery of antibiotics and DNase using an inhalable particle system may be a promising strategy for local antipseudomonal therapy in the CF airway.

We report the different oxidation behavior between polycrystalline chemical-vapor-deposited and mechanically exfoliated single crystal MoS 2 monolayers by ultraviolet-ozone treatment. As ultraviolet-ozone treatment time increased from 0 to 5 min, photoluminescence emission and Raman modes of both MoS 2 disappeared, suggesting structural degradation by oxidation. Analysis with optical absorbance and X-ray photoelectron spectroscopy suggested the formation of MoO 3 in both MoS 2 after ultraviolet-ozone treatment. In addition, ultraviolet-ozone treatment possibly led to the formation of oxygen vacancies, molybdenum oxysulfide, or molybdenum sulfates in chemical-vapor-deposited MoS 2 . The measurement of electrical resistance after ultraviolet-ozone treatment suggested the transformation of chemical-vapor-deposited MoS 2 into doped MoO 3 and of mechanically exfoliated MoS 2 into negligibly doped MoO 3 . These results demonstrate that the crystallinity of monolayer MoS 2 can strongly influence the effect of ultraviolet-ozone treatment, providing important implications on the device integration of MoS 2 and other two-dimensional semiconductors. Electronic supplementary material The online version of this article (10.1186/s11671-019-3119-3) contains supplementary material, which is available to authorized users.

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We report the photoluminescence quenching in monolayer MoS2, MoSe2, WS2, and WSe2 by atomic layer deposited Al2O3 encapsulation. The negative shift and broadening of photoluminescence emission suggested electron doping after encapsulation. The further reduction, softening, and broadening of the A1g mode in Raman spectra also suggested electron doping after Al2O3 encapsulation. To investigate the origin of photoluminescence quenching, we fabricated bottom-gate MoS2 transistors on SiO2/Si substrates. Under a 405-nm-laser, Al2O3-encapsulated MoS2 transistors exhibited enhanced electron photocurrent, suggesting that photoluminescence quenching was dominated by hole transfer to encapsulation-induced trap states. These results demonstrated the importance of defect control for the dielectric deposition in achieving high-performance optoelectronic devices based on monolayer transition metal dichalcogenides.

We report the oxidation behavior of mechanically-exfoliated WS 2 and WSe 2 monolayers by ultraviolet-ozone treatment. After 1 min of ultraviolet-ozone treatment, photoluminescence and Raman measurement suggested the oxidation-induced doping of WS 2 and WSe 2 . As the duration of ultraviolet-ozone treatment increased to 6 min, the quenching of photoluminescence and Raman spectra suggested severe oxidation of WS 2 and WSe 2 . While x-ray photoelectron spectroscopy measurement suggested the oxidation of ultravioletozone treated WS 2 and WSe 2 into WO 2 or WO 3 , the formation of WO 3 was confirmed by the measurement of transistor characterisitics of oxidized WS 2 and WSe 2 . These results demonstrate that the oxidation behavior of WS 2 and WSe 2 monolayers significantly depends on the conditions of ultraviolet-ozone treatment, highlighting the importance of process optimization for the device integration of transition metal dichalcogenides including WS 2 and WSe 2 .