X-ray-induced persistent photoconductivity in vanadium dioxide

Abstract

The resistivity of vanadium dioxide (VO2) decreased by over one-order of magnitude upon localized illumination with x-rays at room temperature. Despite this reduction, the structure remained in the monoclinic phase and had no signature of the high-temperature tetragonal phase that is usually associated with the lower resistance. Once illumination ceased, relaxation to the insulating state took tens of hours near room temperature. However, a full recovery of the insulating state was achieved within minutes by thermal cycling. We show that this behavior is consistent with random local-potential fluctuations and random distribution of discrete recombination sites used to model residual photoconductivity.

Mesoscopic structural phase progression in photo-excited VO2 revealed by time-resolved x-ray diffraction microscopy

“…3). The focused x-ray beam may alter the electronic properties of VO2 41 , but no structural modification of the sample was observed during our measurements. The average diffraction intensities across the entire 10 × 10 μm 2 maps are…”

Pure electronic metal-insulator transition at the interface of complex oxides

“…Cr-doped V 2 O 3 15 and the surface driven Ca 1.9 Sr 0.1 RuO 4 47 . It should be noted, experiments have also reported evidence of photoinduced MITs without resolved structural transitions 63 64 . Finally, these measurements are sensitive to long range ordering and do not rule out the possibility of a short-range charge ordered state on Ni or bond-centered ordering 65 66 .…”

Physical property exploration of highly oriented V2O5 thin films prepared by electron beam evaporation

“…[8][9][10][11][12][13] Dietze et al have illustrated the feasibility of using VO 2 as a potential candidate for photoconductive devices. 14 Apart from these, V 2 O 5 finds applications in sensors, 15 actuators, 16 magnetic applications 17 and fiber optic devices. 18 Furthermore, tuning of thickness, morphology and particle size has a pronounced effect in altering the properties of any material due to the enhanced surface to volume ratio and dimensions.…”