Review on vacuum ultraviolet generation in low‐pressure plasmas

Abstract

Low‐pressure nonequilibrium plasmas can be a source of intense radiation in the vacuum ultraviolet (VUV) range which can play an important role in the surface modification of solid materials. Herein, we review the available literature on VUV radiation from low‐pressure gaseous plasmas sustained by inductively and capacitively coupled radiofrequency discharges, microwave, and magnetized discharges. The reported VUV fluxes range from about 1014–1017 photons cm−2·s−1 while electron density range from 109 to 1012 cm−3. The correlations between the measured VUV fluxes and parameters, such as gas pressure, electron density, and discharge power are shown. The results summarized in this study represent a rough guide for the scientists involved in plasma–surface interactions. As the flux of VUV photons depends on numerous parameters, it is currently only possible to estimate its order of magnitude.

Non-Equilibrium Plasma Methods for Tailoring Surface Properties of Polyvinylidene Fluoride: Review and Challenges

“…A high dissociation fraction of oxygen molecules persists even in late afterglows, where other reactants are absent. Oxygen plasma is also a source of VUV radiation at about 130.4 nm arising from the resonant transition of O atoms [ 27 ], although the radiation is not as extensive as that from argon plasma at identical conditions [ 28 ]. The two necessary requirements for surface activation are therefore satisfied when using oxygen plasma: VUV radiation for breaking C–F bonds or the polymer chain and O atoms for the occupation of the dangling bonds.…”

Experimental Study of Irradiation of Thin Oxide and Mo/Si Multilayers by High Brightness Broadband VUV/UV Radiation and Their Degradation

“…As mentioned [30,31], characteristic values of energy are approximately up to 10 10 -10 11 photon/s per single pulse for synchrotron radiation. Our fluxes are higher than other low-pressure plasma emitters allow (up to 10 17 photon/s for a single pulse) [32]. Besides, synchrotron radiation is strongly directed and creates mainly local high-temperature fields and stress gradients when irradiating.…”

Hydrophobic Recovery of Plasma-Hydrophilized Polyethylene Terephthalate Polymers

“…Another scientific challenge is the determination of the role played by the photon energy. The low-pressure plasma is a suitable source of such radiation, and plasmas sustained in different gases will provide VUV radiation peaking at different wavelengths [51]. The synergies between the VUV photons and reactive oxygen species (particularly neutral oxygen atoms) also represent a scientific challenge not tackled yet in the case of PET samples.…”