We report on two-step current-induced effects on the electrical, optical, and structural properties of VO2 films around the Metal–Insulator Transition (MIT) in synergy with ambient temperature (T). Simultaneous electrical resistance and transmittance measurements of VO2 semitransparent thin films as a function of T show that the electric current modifies the MIT that takes place in two steps: an abrupt change that increases upon increasing current, implying the formation of larger metallic domains within the current path, accompanied by a smoother change that follows the temperature change. Resistance measurements of thicker bulk-like VO2 films have been also investigated exhibiting similar two-step behavior. By monitoring the specimen temperature (To) during resistance measurements, we show that the abrupt resistance step, accompanied by instantaneous heating/cooling events, occurs at temperatures lower than TMIT and is attributed to current-induced Joule heating effects. Moreover, by monitoring To during current–voltage measurements, the role of T in the formation of two-step current modified MIT is highlighted. X-ray diffraction with in situ resistance measurements performed for various currents at room temperature as a function of To has shown that the current can cause partially MIT and structural phase transition, leading to an abrupt step of MIT. The formation of a rutile metallic phase of VO2 under high applied currents is clearly demonstrated by micro-Raman measurements. By controlling current in synergy with T below TMIT, the VO2 film can be driven to a two-step current-induced MIT as gradually a larger part of the film is transformed into a rutile metallic phase.

Visible Light Communication (VLC) systems use light-emitting diode (LED) technology to provide high-capacity optical links. The advantages they offer, such as the high data rate and the low installation and operational cost, have identified them as a significant solution for modern networks. However, such systems are vulnerable to various exogenous factors, with the background sunlight noise having the greatest impact. In order to reduce the negative influence of the background noise effect, optical filters can be used. In this work, for the first time, a low-cost optical vanadium dioxide (VO2) optical filter has been designed and experimentally implemented based on the requirements of typical and realistic VLC systems in order to significantly increase their performance by reducing the transmittance of background noise. The functionality of the specific filter is investigated by means of its bit error rate (BER) performance estimation, taking into account its experimentally measured characteristics. Numerous results are provided in order to prove the significant performance enhancement of the VLC systems which, as it is shown, reaches almost six orders of magnitude in some cases, using the specific experimental optical filter.

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