Enhanced exclusive-OR and quick response code-based image encryption through incoherent illumination

The usage of BaSO4 nanoparticles on WLEDs luminous flux and color uniformity improvements have been analyzed and demonstrated in this manuscript. The mixture of BaSO4 and silicone placed on the yellow phosphor layer benefits the internal light scattering and thus enhances the angular correlated color temperature (CCT) homogeneity. Specifically, the blue-light intensity at large angles tend to increase and results in light intensity discrepancy, which can be corrected with added BaSO4. In addition to this, the BaSO4-silicone composite modifies the refractive index of the air-phosphor layer interface to an appropriate value, and thus, the luminous efficiency increases. The results show that the CCT deviations is reduced by 580 K, from 1000 K to 420 K, within the angle range from -70 0 to +70 0 with BaSO4 in the phosphor structure. The increase in luminous flux is also recorded by 2.25%, in comparison with that of the non-BaSO4 traditional structure, at the 120-mA driving current. Hence, integrating BaSO4 nanoparticles into the remote phosphor structure can contributes to the enhancement of both lumen output and CCT uniformity.

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“…The general definition of the angular-dependent CCT homogeneity can be demonstrated as the following equation [23][24][25]:…”

Section: Resultsmentioning

confidence: 99%

Effects of BaSO4 nano-particles on the enhancement of the optical performance of white LEDs

2021

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“…Because of the 4f electron layer arrangement of rare earth elements, the related compounds have a wide range of fluorescence properties. Because Tb 3+ has a 4f 8 power state as well as being easily influenced by its surroundings, samples containing Tb 3+ have a superior fluorescent excitation as well as discharge spectrum [4]. Tb 3+ also possesses an excited lengthy state duration as well as an uncomplicated discharge apex cleaving mode.…”

Section: Introductionmentioning

confidence: 99%

Selection of Gd2(WO4)3:Tb3+ for inproving color deviation in white light-emitting diodes

Thi

Anh

2022

IJEECS

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This study successfully using the hydrothermal technique to synthesize <a name="_Hlk81726620"></a>Gd2(WO4)3:Tb3+ phosphors when subjected to calcination under the temperature of 900°C. Here are some aspects that were thoroughly examined: the crystal formation, photoluminescence, photoluminescence excitation, as well as fluorescent degradation for the samples. The (Gd2-xTbx)(WO4)3 (x=0.01-0.15) phosphors exhibit a bright discharge of green under 547 nm (5D4→7F5 shift for Tb3+) when excited at 270 nm (4f8→4f75d1 shift for Tb3+). Because of the exchange interaction between Tb3+, the quenching concentration was determined to be around 10%. The addition of Tb3+ had no effect on the (Gd2-xTbx)(WO4)3 phosphors' CIE chromaticity coordinates (~0.33±0.02, ~0.60±0.02) or color temperatures (~5542 K). Nevertheless, when the Tb3+ content increased, the fluorescence lifespan for 547 nm emission reduced due to energy transfer between Tb3+. The strong green emission from Gd2(WO4)3:Tb3+ phosphors is a potential element for WLEDs and display areas.

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“…For instance, we developed a three-range WLED backlighting with a hue range of up to 92% NTSC [1] using promising green β-sialon:Eu 2+ and red CaAlSiN3:Eu 2+ [9]- [11]. Xu et al [12] assessed a fascinating green Sr3Si13Al3O2N21:Eu 2+ and succeeded in constructing a WLED backlighting with a 94.2% color scale [13], [14]. Anh et al [15] obtained a 90% NTSC hue range by using green SrGa2S4:Eu 2+ and red CaS:Eu 2+ films for WLED backlighting.…”

Section: Introductionmentioning

confidence: 99%

High-efficiency green and red phosphors enable a broader hue-gamut light-emitting diode backlight for brighter displays

Thi

2022

IJEECS

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In this article, we suggest combining a blue InGaN chip with strait-band green (β-sialon:Eu2+), red (K2SiF6:Mn4+) phosphors to create WLED devices with a wide hue range and high effectiveness that may be utilized in LCD backlighting. The highest radiation wavelength of a gas-pressure sinted β-sialon:Eu2+ is 535 nm, the full width at half maximum (FWHM) is 54 nm, and the outside quantum performance is 54.0% lower than the 450 nm stimulation. We created K2SiF6:Mn4+ in two steps. The phosphor possesses a sharp line radiation spectrum accompanied by the most intense maximum point under 631 nm, an FWHM reaching roughly 3 nm, as well as an exterior quantum effectiveness of 54.5%. When computed at 120 mA, the manufactured three-range wLEDs had an illuminating performance of 91–96 lm/W and a large color temperature of 11,184–13,769 K (i.e., 7,828–8,611 K in LCD screens). The hue range represented by the CIE 1931 and CIE 1976 hue gaps is 85.5-85.9% and 94.3-96.2% of the NTSC requirement, respectively. The optic characteristics outperform those of phosphor-transformed wLED backlights utilizing broad-range green or red phosphors, indicating the two strait-range phosphors studied are the best luminous substances for producing brighter and livelier screens.

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Enhanced exclusive-OR and quick response code-based image encryption through incoherent illumination

Cited by 32 publications

References 43 publications

Effects of BaSO<sub>4</sub> nano-particles on the enhancement of the optical performance of white LEDs

Effects of BaSO<sub>4</sub> nano-particles on the enhancement of the optical performance of white LEDs

Selection of Gd2(WO4)3:Tb3+ for inproving color deviation in white light-emitting diodes

High-efficiency green and red phosphors enable a broader hue-gamut light-emitting diode backlight for brighter displays

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