Electroluminescent characteristics of ZnGa₂O₄:Dy³⁺ thin film devices fabricated on glass substrates

Abstract

An alternating current thin film electroluminescent (ACTFEL) device was fabricated on commercial glass substrate with dysprosium doped zinc gallate as the active layer. The phosphor layer and the top dielectric layer were deposited using rf magnetron sputtering technique. The devices fabricated with an asymmetric double insulating structure gave a white electroluminescent (EL) emission when driven by a voltage pulse frequency of 1.5 kHz, even without post‐deposition annealing of the active layer. Such an emission resulted from the simultaneous occurrence of multicolor transitions, characteristic of the dopant ion. The exponential dependence of luminance on applied voltage was quite evident from the luminance–voltage (L–V) curves. Devices were also fabricated with a highly crystallized interfacial layer of ZnO in between the substrate and the phosphor layer. Such devices could withstand a wider range of applied voltage, henceforth resulting in enhanced device performance. The chromatic quality of the EL emissions from both the devices were gauged using chromaticity coordinates. The CIE coordinates of fabricated ZnGa2O4:Dy3+ ACTFEL devices (a) without and (b) with ZnO interfacial layer.

Investigating the Thermo-Optic Properties of BCZT-Based Temperature Sensors

“…However, upon increasing the calcining temperature or dwell time to 1200 °C for 4 h, 1250 °C for 2 h, and 1250 °C for 4 h, the unidentified phase disappeared. The resulting XRD patterns had a pure perovskite without a secondary peak of impurity [ 30 , 31 ]. Regarding the expanded XRD patterns for 2θ = 36–49°, the split of the single peaks of (111) reflections was observed at 2θ~38° to 40° and the single peak of (002) reflection at 2θ~44° to 46° in all samples used in this study [ 33 ].…”

“…Subsequently, a four-layer film structure was constructed, consisting of an electrode layer, a dielectric layer, a phosphor layer, and a translucent conductive layer. The dielectric value of the dielectric layer was adjusted to facilitate electroluminescence of the cations in the phosphor layer through the activation mechanism of host-lattice energy transfer [ 29 , 30 , 31 , 32 ]. Modifying the dielectric value based on temperature variations resulted in corresponding changes in fluorescence, enabling the development of a compact and efficient opto-thermal sensor.…”

Synthesis and luminescent properties of magnesium gallate spinel doped with Mn2+ and Eu3+ ions

“…The most intense f-f excitation line was found at 393 nm that corresponds to 7 F 0 → 5 L 6 transitions in Eu 3+ ions. The emission of Eu 3+ ions is presented by sharp lines that correspond to f-f transitions in 4f 6 configuration of Eu 3+ ions. The most intense emission line of Eu 3+ ions was found at 617 nm and appropriative to 5 D 0 → 7 F 2 electric-dipole transitions.…”

“…Magnesium gallate spinels have bandgap around 5 eV [5]. Despite that, gallates demonstrate semiconductor properties that can be applied in modern liquid-panel displays [6].…”

Investigating the Effect of Calcine Temperature and Dwell Time on Electroluminescent Films in BCZT Ceramics

“…We then constructed a film consisting of four main layers: an electrode layer, a dielectric layer, a phosphor layer, and a translucent conductive layer. To stimulate electroluminescence of the cations of the phosphor layer through the host-lattice energy transfer activation mechanism, the dielectric value of the dielectric layer was changed [25][26][27]. Adjusting of the dielectric value according to temperature resulted in corresponding changes in fluorescence, allowing for the development of a thin and small temperature-measuring device.…”