Illumination Applications Research Articles

Identifikasi Skema Pencahayaan Terhadap Ketertarikan Pengunjung Pada Koridor Jalan Asia Afrika Bandung


 Abstract: Public space is one of the most common areas in a city. In the urban area, the image arises from a variety of natural aspects, such as art, culture, history, made-to-measure architecture, facilities, and its infrastructure in public space. This research is aimed at the attraction of users towards street corridor and facade illlumination along Asia Afrika street corridor The analysis is done using quantitative methods in form of questionnaire toward the respondents. The results of this research show that the application of illumination at Asia Afrika Street corridor and building facade affect the attraction and interest of the visitors to the area.
 Keywords: attraction; city lighting; public space; street corridor; street illumination

Microminiature Pressure Sensors Based on Diode Structures

The paper analyzes modern microminiature pressure sensors made on various diode structures, in particular on organic light-emitting diodes, field-effect transistors, photovoltaic elements and multi-circuit piezoresistive sensors. The possible areas of application of such sensors, their main advantages and disadvantages are shown. The study of 4 groups of samples of diode heterostructures based on CdS / ZnS / CuS / CdTe was carried out and the perspective of using pressure sensors based on these materials as an analogue of existing semiconductor devices was shown. On the basis of experimental studies with the application of pressure, twisting and illumination, it is substantiated that these structures are piezoelectric. The complete technological process of the step-by-step creation of these structures is presented. The obtained structures were analyzed: structural diagrams, current-voltage and piezoelectric characteristics in comparison with the characteristics of other piezoelectric materials are given. Possible areas of application of such structures are described. The provided design schemes and parameters of the obtained diode structures may be of interest to a wide range of specialists in the field of sensor technology and automation of various technological processes of microelectronic equipment manufacturing. It is shown that by changing the sensor manufacturing technologies and the concentration of chemical elements in the obtained films, it is possible to change the sensitivity of the sensor and the dynamic range of its operation, adapting the sensor parameters to the field of its application in the relevant measuring electronic equipment and pressure control systems.

A nitriding garnet structure cyan emitting phosphor Ca2(Y, Ce)Hf2(Al, Si)3(O, N)12 with high efficiency and excellent thermal stability

Cyan phosphors with high efficiency and excellent thermal stability are an important part for application in full spectrum illumination. Herein, a series of nitriding cyan emission phosphors Ca2(Y, Ce)Hf2(Al, Si)3(O, N)12 with garnet structure are successfully synthesized, their phase purity, crystal structure, morphology, elemental composition and valence state are analyzed in detail, and the results indicate that a small amount of Si3N4 doping does not cause impurity phase. The phosphor has an efficient broadband cyan emission at 493 nm with full width at half maximum (FWHM) of about 95 nm under 411 nm excitation. Impressively, the luminous intensity of the nitriding phosphor is increased by 30%, the internal/external quantum efficiency are increased from 41.63% and 40.01% to 61.93% and 52.13%, and the thermal stability is improved from 75%@150 oC to 85%@150 oC, which is even better than the commercial green phosphor LMS520B (77%@150 oC). Finally, a full-visible-spectrum LED with low correlated color temperature (CCT = 5143 K) and high color rendering index (Ra = 98.3) is fabricated by employing Ca2(Y, Ce)Hf2(Al, Si)3(O, N)12 phosphors as cyan emitting component. The results indicate that the nitriding Ca2(Y, Ce)Hf2(Al, Si)3(O, N)12 phosphors have potential to act as cyan emission phosphors for full-visible-spectrum LEDs.

Crystal configuration and luminescence dynamics of highly efficient green-glimmering vanadate-based Ca9Gd(VO4)7: Er3+ nanomaterials pertinent for next-generation illumination applications

Crystal configuration and luminescence dynamics of highly efficient green-glimmering vanadate-based Ca9Gd(VO4)7: Er3+ nanomaterials pertinent for next-generation illumination applications

Optical properties of YMASG:Ce fluorescent ceramics prepared by hot-pressure sintering

Cerium-doped yttrium aluminum garnet (YAG:Ce) based transparent ceramics have been widely used in fluorescent lighting as high-quality inorganic fluorescent conversion materials. This paper further explores the Mg2+-Si4+ ions doped YAG:Ce transparent ceramics by combining the solid-phase reaction method with vacuum hot-pressure sintering and implementing protection measures against hot-pressure mold contamination, and also investigates the effect of different Mg2+-Si4+ doping contents on the structure, transmittance and luminescence properties of the ceramics under hot-pressure sintering. In this work, pure-phase YMASG:Ce transparent fluorescent ceramics with a grain size of about 3-6 μm and clear and clean grain boundaries were obtained with an In-line transmittance of 67% at 800 nm. Under the excitation at 460 nm, the emission peak was red-shifted by 26 nm and the full width at half maxima (FWHM) was broadened with the increase of Mg2+-Si4+ content, which shows that the Mg2+-Si4+ ion pair effectively complements the absence of the red light component in the YAG:Ce emission spectrum. The optimized YMASG:Ce ceramics obtained high-quality warm white light with a low correlated color temperature (CCT) and a high color rendering index (CRI) under the excitation of the blue LED chip. This work proved the feasibility of vacuum hot-pressure sintering to prepare YMASG:Ce transparent fluorescent ceramics, and provided a new approach for studying YMASG:Ce-based ceramics, which was significant for the application of high-power visible laser illumination.

Combined application of exogenous phytohormones and blue light illumination to the marine diatom Phaeodactylum tricornutum

Diatoms constitute a diverse group of photosynthetic microorganisms with great potential for biotechnological applications. Compounds which they can synthesise, such as ω3-fatty acids or carotenoid pigments, can find uses in the pharmacology, nutraceutical or cosmetic sectors. However, a major challenge to date has been to stimulate the synthesis of valuable metabolites without hampering cell growth.In this study, the model microalgal species Phaeodactylum tricornutum (marine diatom) was subjected to blue light illumination and phytohormonal supplementation (gibberellic acid, GA3, and abscisic acid, ABA) as single factors or in combination. P. tricornutum was grown under a batch culture regime for 30 days and treatments were tested at two different stages (day 0 and day 20).The highest yield of dry biomass was obtained when combining blue light and GA3 from day 0 (25 % higher than control) while no relevant variation occurred when applying blue light from day 20. When applied from day 0, blue light led to a reduction in the fucoxanthin and PUFA content of the biomass. Single dose supplementations of the phytohormones seemed less dependent on the time of application. When applied without blue light, GA3 (2 mg/l) increased the fucoxanthin content and yield by 25 and 30 %, respectively. However, the co-supplementation of GA3 and ABA (2 mg/l) was more effective than single applications, significantly boosting fucoxanthin yield up to 1.3 mg/l and EPA proportions by 17 %, compared to the control set. These increments were also associated with enhanced antioxidant activity (60 % increment).These results highlight the importance of optimising the timing of application of treatments to avoid deleterious effects on pigment and PUFA accumulation in cells. Switching to blue light illumination and applying GA3 and ABA later in the growth of the diatom P. tricornutum constitutes a promising strategy to improve its yields in high-value metabolites prior to biomass harvest.

Simultaneous realization of tunable luminescence and enhanced thermal stability in Eu2+-based blue-green phosphors for multifunctional applications

Developing a new Eu2+-doped blue-green phosphor with tunable spectral in silicate materials is challenging for a high-quality phosphor-converted white light-emitting diode. The cation substitution strategy is a valid way to concurrently modify spectral characteristics and optimize luminescence performances. Herein, a series of NaBaScxLu1-xSi2O7: Eu2+ phosphors with blue-green color-tunable luminescence have been designed. By modulating the ratio of Sc/Lu, controllable regulation of the photoluminescence and thermal stability properties can be realized simultaneously. Moreover, the initial emission intensity is monotonically increased by 2.92 times and the quantum efficiency is enhanced dramatically by introducing Sc3+. Especially, the thermal stability is boosted from 53.4% to 90.9% and the emission shifted from 485 to 504 nm is improved due to the chemical substitution of Sc in the Lu site with the lattice shrinks resulting in the Eu5d energy level farther away from the conduction band and a minimum 5d energy level closer to the ground state energy level. Furthermore, the fabricated w-LEDs with NaBaScxLu1-xSi2O7: Eu2+ blue-green phosphors and (Sr, Ba)3SiO5: Eu2+ red phosphor exhibit a high color rendering index (Ra = 87.2) and desired color-dependent temperature (CCT = 3711 K). Except for the application in solid-state illumination, the potential application of synthetic phosphors in optical anti-counterfeiting is also explored. The luminescence tunable strategy via cation substitutions simultaneously modifies emission and improves thermal stability, providing a distinctive design philosophy for the development of Eu2+-doped silicate phosphors.

Ultrahigh Power Density LuAG:Ce Green Converters For High‐Luminance Laser‐Driven Solid State Lighting

AbstractLu3Al5O12:Ce (LuAG:Ce) phosphor has been designed and fabricated into various forms of green fluorescent converters and plays a critical role in the field of solid‐state laser lighting. Phosphor in glass (PiG) and phosphor in glass film (PiGF) are expected to be viable strategies for high‐power and high‐brightness laser diode (LD) illumination due to their easy synthesis and low cost. In this study, LuAG:Ce‐PiG with an internal quantum efficiency of 90.5% is prepared by investigating the sintering conditions and combining with a borosilicate glass. It possesses a luminous flux (LF) of 584 lm and luminous efficiency (LE) of 225 lm W−1 @ 20 W mm−2. On this basis, LuAG:Ce‐PiG sapphire film (LuAG:Ce‐PiGSF) with high thermal conduction (10.26 W (m K) −1) is successfully sintered on the sapphire to obtain the LF of 833 lm and LE of 252 lm W−1 @ 36.36 W mm−2. The maximum tolerated power density can reach 45.45 W mm−2. In addition, when the color converters are placed in a commercial LD transmission module and continuously light for 24 h at 16.5 W, the relative light intensity only decreases by 14.15% and 12.82%, respectively. Therefore, it is believed that the work has promising applications in laser illumination and accelerating the development of LD lighting.

High Color Stability Blue-to-Violet Room Temperature Phosphorescent Carbon Dot Composites with Ultralong Lifetime for Information Encryption

Ultralong room temperature phosphorescent (RTP) materials have a wide range of applications in information encryption, bio-imaging, optoelectronics, and display and illumination. Among them, blue-emitting RTP materials with high quantum yield (QY) and ultralong luminescence have been a challenge in the field of RTP materials. Herein, we prepared blue-to-violet RTP carbon dot (CD) composites with high color stability by mixing boric acid with pyromellitic acid, trimesic acid, and terephthalic acid, separately, and pyrolyzing them at identical temperature conditions, leading to CD composites with emission peaks at 440, 407, and 430 nm, respectively. This strategy enables the precursors to effectively suppress the deactivation of the triplet state through covalent bonding (B–C bond) and hydrogen bonding interactions and confinement in a highly rigid B2O3 polycrystalline network, thereby successfully producing blue-to-violet CD composites with high QY (49, 64, and 78%, meanwhile, their phosphorescence QY can reach 47, 57, and 65%), ultralong lifetime (0.633, 1.882, and 2.332 s, respectively), and high color stability. Owing to the unique properties, the CD composites show great potential for application in the field of anti-counterfeiting and information encryption.

Achieving bright green emission in Tb3+ doped ternary yttrate-based nanocrystalline powder for solid-state illumination applications

Tb3+ activated ternary yttrate-based nanophosphor series was fabricated via a simple solution combustion (SC) methodology. An orthorhombic crystal lattice havingspace group Pnma (62) with irregularly shaped particles with sizes between 32 and 54 nm was formed. Morphological features and elemental analysis were examined via TEM, SEM, and EDAX techniques, respectively. On near-ultraviolet (NUV) stimulation, luminescence spectra presented a bright green emission at 18315 cm−1 wavenumbers consistent with the electronic transition 5D4→7F5. The decay lifetimes, quantum efficiency, and non-radiative rates were also examined. The critical distance (Rc) originated to be 20.21 Å inducing the multipolar interrelations as the probable route for concentration quenching. The energy bandgap was examined via Diffuse Reflectance Spectroscopy (DRS). A brilliant luminescence profile is also replicated in green coordinates (0.2531, 0.4998) and 7479 K (color temperature), which has been committed to typical television, European-Broadcasting-Union (EBU), NICHIA-LED green coordinates, pc-WLEDs, and another solid-state lighting (SSL) applications.

Self-filtering illumination source and application in fluorescence imaging

To date, fluorescence imaging systems have all relied on at least one beam splitter (BS) to ensure the separation of excitation light and fluorescence. Here, we reported SiO2/TiO2 multi-layer long pass filter integrated GaN LED. It is considered as the potential source for imaging systems. Experimental results indicate that the GaN LED shows blue emission peaked at 470.3 nm and can be used to excite dye materials. Integrating with a long pass filter (550 nm), the light source can be used to establish a real-time fluorescence detection for dyes that emit light above 550 nm. More interestingly, with this source, a real-time imaging system with signature words written with the dyes, such as ‘N J U P T’, can be converted into CCD images. This work may lead to a new strategy for integrating light sources and BS mirrors to build mini and smart fluorescence imaging systems.

Synthesis of group I–III–VI semiconductor quantum dots and its application in food safety testing

Abstract As a good fluorescent material, most I–III–VI ternary semiconductor quantum dots (QDs) do not contain heavy metal elements such as Cd and Pb and thus have low toxicity. In addition, they also have excellent data performance such as narrow band gap, large absorption coefficient, large Stokes shift, low self-absorption effect, and luminescence wavelength in the near infrared region. I–III–VI QDs also have a size-dependent luminescence in the visible and near-infrared ranges, and their fluorescence quantum yields can exceed 50% especially when coated with ZnS shells, thus offering great potential for applications in illumination, display, and bioimaging. The review focuses on the synthesis of group I–III–VI QDs, their properties, and applications. In the first part, we discuss the approaches to synthesize these QDs. In the second section, we provide an overview of the applications of I–III–VI QDs in food safety detection, with emphasis on the detection of heavy metal ions, foodborne pathogens, food additives, pesticide, and veterinary drug residues. The final section summarizes the current application prospects of ternary semiconductor QDs.

Spatially modulated light harvesting with plasmonic crescent metasurface.

Harvesting light by metallic structures with sharp corners, or the so-called photonic singularities, has exhibit their potential in nanophotonics, sensing, and bio-medical applications. The high-quality light confinement of the light energy mainly relies on the precise preparation of nanoscale photonic singularities. However, the realization of massive photonic singularities still meets the challenges on integration and low-cost mask multiplexing. Here, we show an angle-dependent elevated nanosphere lithography to achieve massive photonic singularities for spatially modulated light harvesting at the near-infrared regime. The photonic geometrical singularity is constructed by the gold crescent array of plasmonic materials. The numerical simulation shows that the light can be localized at the spatially distributed singularities. This phenomenon is verified experimentally through the infrared spectral measurement. Our work provides the possibility to produce integrated light-harvesting devices for numerous optical applications in illumination, display, and enhanced nonlinear excitation.

Green Upconversion of a SrLaAlO4:Yb,Er Phosphor and Its Application for LED Illumination

Green Upconversion of a SrLaAlO4:Yb,Er Phosphor and Its Application for LED Illumination

One-shot detection limits of time-alignment two-photon illumination radar

Quantum radar has recently gained increasing importance in a number of military applications. The estimation accuracy of one-shot quantum illumination events is significant in target detection. However, the accuracy is inevitably deteriorated by measurement noises. The traditional one-shot illumination emits a single photon towards a certain area which thermal noise exists in the path to, and the states of the received photons are hard to distinguish in the following processing. Therefore, a new optical probe source is proposed in this work. The independent detecting unit in the enhanced illumination is comprised of two photons aligned in time by using Hong–Ou–Mandel (HOM) interferometer. Further, one-shot detection in a general discrete model is realized and it proves a significant promotion in accuracy. The expansion of useful parts in parameter space and the lower minimal error probability for hypothesis testing have been mathematically demonstrated. The accuracy of one-shot detection can be effectively improved by the proposed scheme implying that it possesses great potential applications in quantum illumination and imaging.

Lead-free zero-dimensional Cs2ZnBr4 perovskite single crystals with broadband emission covering visible spectrum

All-inorganic lead-free zero-dimensional (0D) metal halides perovskites with intriguing photoluminescent (PL) properties have aroused much interest due to their application in lighting and artificial illumination. Herein, 0D Cs2ZnBr4 perovskite single crystals were synthesized through simple solvothermal method. The phase purity, the electronic band structure and electronic density of states of Cs2ZnBr4 are investigated by X-ray diffraction (XRD) measurement and density functional theory (DFT) calculation. Under 430 nm blue light excitation, Cs2ZnBr4 single crystals exhibit broadband emission covering the visible region from 450 to 750 nm and large Stokes shift about 120 nm, originating from self-trapped excitons (STEs) radiative recombination. And Cs2ZnBr4 shows excellent thermal and air stability. These results indicate the potential application of Cs2ZnBr4 as environmental-friendly light emitters for solid state lighting and displaying.

Emission-enhanced high-performance Al2O3–Ce: (Y, Tb)AG composite ceramic phosphors for high-brightness white LED/LD illumination

Owing to their excellent thermal robustness, high light saturation threshold, and high luminous efficiency, Al2O3–Ce doped garnet composite ceramic phosphors (CCPs) have attracted extensive attention for applications in laser illumination. In this study, we fabricated the high-performance Al2O3–Ce: (Y, Tb)3Al5O12 CCPs via a solid-state reaction. It was found that the bidirectional energy transfer process between Ce3+ and Tb3+ can promote the absorption of Ce3+ for blue light, which can effectively enhance the yellow light emission intensity and reduce the correlated color temperature (CCT) of samples. Based on this effect, Al2O3–Ce: (Y0·9Tb0.1)3Al5O12 CCPs show the best thermal quenching and luminous efficiency performance. Its luminous efficiency at 450 K drops by 17% from the initial luminous efficiency, and its luminescence efficiency reaches 262 lm/W when driven by a 2.24 W blue laser. In addition, the CCT of samples gradually decreases from 8329 K to 4460 K with the increase of Tb3+, which is of great significance for realizing the white LD lighting.

Ba3(ZnB5O10)PO4:Tb3+ green phosphor: Microwave-assisted sintering synthesis and thermally stable photoluminescence

Green phosphor has become increasingly an attractive focus owing to its multifunctional applications in illumination, display, anti-counterfeiting, and even bio-labeling. In this paper, trivalent terbium (Tb3+)-activated Ba3(ZnB5O10)PO4 (BZBP) green phosphors were synthesized at 1050 K for 1 h via a microwave-assisted sintering route. The structural study, influence of dopant Tb3+ content and working temperature on photoluminescence behavior, and colorimetric properties were performed comprehensively. Tb3+ successfully substitutes Ba2+ in the BZBP lattice. Under 378 nm near-ultraviolet (NUV) excitation, the emission bands peak at 488, 542, 585, and 623 nm, corresponding to the 5D4→7F6, 5D4→7F5, 5D4→7F4, and 5D4→7F3 transitions of Tb3+, respectively. Despite the working temperature increases, the title phosphor maintains the high emission intensity and low chromaticity shifting, exhibiting robust thermostability and color stability. This work provides a simple and rapid synthesis method for borophosphate-based phosphor. The application of NUV-excited white light-emitting diodes fabricated with the title product and commercial phosphors (red, blue) indicates that the developed green phosphor BZBP:Tb3+ is a promising candidate material in illumination and display applications.

Comparative Analysis of High-Pressure Sodium Vapor Luminaires with LED Luminaires in Tunnel Illumination

Nowadays, some roads pass through underground tunnels due to technical inadequacy and high economic costs in constructing highways, railways, and pedestrians. Tunnels are opened to pass through obstacles on the route (mountain, hill, etc.) to force the driver, disturb him, reduce the ramps that could endanger safety depending on nature’s state, and shorten travel distances. In this way, number of tunnels along with the road increases, and illuminating these tunnels with different characteristics varies day and night. Tunnel illumination calculations and applications are essential as good tunnel illumination ensures the same flow of comfort, speed, and safety as on the approaching road. Moreover, with the advancement of tunnel technology, many types of equipment are used inside and outside the tunnel, and electricity needs vary according to these types of equipment. In this research, the importance of tunnel illumination was discussed and comparative illumination analysis in 8 August tunnel in Bitlis was conducted. Illumination for the Bitlis 8 August tunnel was done using luminaires with high-pressure sodium vapor lamps, and the grid was used to generate all the energy required. In this study, the energy used by the Bitlis 8 August tunnel for illumination was obtained from the accurate data and the results were compared with the initial situation when the same system was installed using light emitting diode (LED) illumination technology.

Enhancement of Photocatalytic Degradation by Combination of Light Illumination and Bias Voltages Toward Anti-virus Coating Applications

Enhancement of Photocatalytic Degradation by Combination of Light Illumination and Bias Voltages Toward Anti-virus Coating Applications