Sharp Light Research Articles

Validation of the RR Lyrae period determination in the Pan-STARRS PS1 3π survey with K2

Context. The Pan-STARRS 3π survey has detected hundreds of thousands of variable stars thanks to its coverage and 4-year time span, even though the sampling of the light curves is relatively sparse. These light curves contain only 10–15 detections in each of the five filters (g, r, i, z, y). During the K2 mission, the Kepler space telescope observed along the ecliptic plane with a high sampling frequency, although only for about 80 days in each of its campaigns. Aims. Crossmatching and investigating the RR Lyrae stars observed by both K2 and Pan-STARRS can serve as a valuable tool to validate the classification and period determination of the ground-based survey. Methods. We used the Sesar catalogue of RR Lyrae stars detected by Pan-STARRS. After determining the overlap between the stars observed by both Pan-STARRS and K2, we also considered the Gaia DR3 SOS RR Lyrae catalogue data for the list of these stars wherever it was available. The frequencies of the light variations were calculated by applying the Lomb-Scargle periodogram method on the K2 light curves that were prepared with autoEAP photometry. The calculated frequencies of the stars then were compared with those given in the Sesar catalogue and the Gaia DR3 RR Lyrae catalogue. Results. We found that for the majority of the stars, the classification (95.6%) and the frequency determination (90.1%) of the Pan-STARRS RR Lyrae stars were consistent within 0.03 d−1 with those that we derived from the K2 autoEAP light curves. For a significant subset of the sample, 7.4%, however, an offset of 1 or 2 d−1 was found in the frequencies. These are the result of the sampling of the detections, because Pan-STARRS observations are affected by diurnal cycles, whereas Kepler carried out measurements quasi-continuously. We found that RRc subtypes are significantly more affected (25.3%) than RRab subtypes (3.7%), which is most likely caused by RRc stars having less sharp light curve features. Validation via space-based data will be important for future ground-based surveys, as well.

Optical Properties of Europium-Doped Silicon-Based Thin Films

The integration of a silicon-based light emitter into existing CMOS technology has long been intriguing due to its optoelectronic compatibility with microelectronics [1]. However, the indirect band gap nature of bulk silicon has hindered its effectiveness as a light emitter. In addressing this limitation, rare earth ions have emerged as significantly interesting candidates owing to their unique optical and electronic properties. Rare earth-doped silicon structures have earned special attention as they exhibit sharp light emission in different spectral regions [2] . This notable feature is attributed to the effective excitation of rare earth ions within the host matrix. Efficiently excited rare earth ions can produce visible emissions ranging from infrared to ultraviolet, presenting possibilities in diverse applications such as solid-state lighting, displays, lasers, photovoltaics, and optical communication. The incorporation of rare earth-doped silicon structures presents a promising solution to overcome the challenges posed by silicon's intrinsic properties, thereby paving the way for improved performance across a diverse range of optoelectronic applications. Europium is a attractive rare earth material with two optically active states, Eu2+ and Eu3+, enabling it to generate a diverse range of color emissions extending from blue to red depending on the surrounding matrix [3].In this study, we investigated the optical properties and compositions of europium (Eu)-doped thin films including silicon oxide, silicon oxynitride, and silicon carbonitride. For this purpose, thin films were fabricated by electron cyclotron resonance plasma-enhanced chemical vapor deposition (ECR-PECVD) with in-situ magnetron sputtering on p-type 3" Si (100) substrates. In-situ Eu doping was performed by a radio frequency (RF) magnetron sputtering gun, using a 0.25 in. thick, 2 in. (diameter) 99.9% pure Eu sputtering target. Precursor gases, including silane (diluted in 90% argon), oxygen (diluted in 90% argon), nitrogen (diluted in 90% argon), and ethane were utilized. Annealing was performed on the as-deposited films over a broad temperature range, from 600° to 1100°C, in a nitrogen (N2) environment. Rutherford backscattering spectrometry (RBS) was performed to determine the atomic concentration of the film constituents. Variable angle spectroscopic ellipsometry (VASE) analysis was conducted to investigate the optical properties of the films. Room temperature photoluminescence (PL) experiments were performed using a laser diode excitation source operating at a wavelength of 375nm. Notably, bright visible emission was observed in some of the thin films. Finally, we discuss the influence of the atomic concentration of Eu and the annealing temperature on the emission properties observed in the photoluminescence experiments.[1] F. Azmi, Y. Gao, Z. Khatami, and P. Mascher, “ Tunable emission from Eu:SiOxNy thin films prepared by integrated magnetron sputtering and plasma enhanced chemical vapor deposition ,” J. Vac. Sci. Technol. A, vol. 40, no. 4, p. 043402, 2022, doi: 10.1116/6.0001761.[2] A. Brik et al., “Annealing Effects on Structural Characteristics of Europium Doped Silicon-Rich Silicon Nitride,” Silicon, vol. 14, no. 14, pp. 8417–8425, 2022, doi: 10.1007/s12633-021-01636-w.[3] D. Li, X. Zhang, L. Jin, and D. Yang, “Structure and luminescence evolution of annealed Europium-doped silicon oxides films,” Opt. Express, vol. 18, no. 26, p. 27191, 2010, doi: 10.1364/oe.18.027191.

Novel green/red oxyfluoride phosphors with excellent optical properties for near-UV excited white light emitting diode

Novel eye-sensitive Ba3Nb2O2F12(H2O)2:Tb3+ green and Ba3Nb2O2F12(H2O)2:Mn4+ red oxyfluoride phosphors with extremely strong absorption in the UV region were designed and synthesized by simple co-precipitation strategy. Particularly, Tb3+ ions were doped in this matrix for the first time, which greatly improves their absorption efficiency in the near ultraviolet region (367 nm) and emits sharp green light (544 nm). In addition, the Ba3Nb2O2F12(H2O)2:Mn4+ red phosphors have strong zero phonon line (ZPL) emission at 625 nm, which is conducive to improving the sensitivity of human eye and color purity. Meanwhile, the optical properties of the red phosphor are significantly enhanced via doping K+ cations as charge compensators. Crystal field environment and nephelauxetic effect of the as-prepared phosphors before and after K+ cation doping were systematically analyzed. Moreover, these synthesized red/green phosphors have good thermal stability and moisture resistance. Remarkably, the as-prepared Ba3Nb2O2F12(H2O)2:5%Mn4+ or K0.9Ba2.1Nb2O2F12(H2O)2:5%Mn4+ red phosphors can be directly mixed with the as-synthesized Ba3Nb2O2F12(H2O)2:13%Tb3+ green phosphor coating on 365 nm near-ultraviolet LED chip to package WLED devices with excellent electroluminescence performance. These findings are conducive to opening an avenue for screening the unique structure of optical materials.

Mainapproach - Artificial Intelligence over on Earth Science

The powerful planet on which we all live is Earth. Actually have individuals begun to sort out the complexity of this planet. In the field of natural sound observing, the common estimation is the demonstrates the typical A-weighted Sound Strain Level. This is easy to see yet gives no genuine detail on the substance of the sound scene, which can be key in its effect on those encountering it. Man- made brainpower thinking techniques have demonstrated to areas of strength for be a course of action of Earth predictable fields. Perhaps of the most quickly making in the field of electronic data advancement. In a grouping of Earth research. I'm exploring on reproduced insight enabled progresses like sharp inversion, splendid sensors, and light dealing with to the test. These movements could possibly help with lessening earth vibration by 15 august 2030 Key Words: Earth Science, Earth Vibration, Light Sensor, Earth Spine.

Valley-conserved topological integrated antenna for 100-Gbps THz 6G wireless.

The topological phase revolutionized wave transport, enabling integrated photonic interconnects with sharp light bending on a chip. However, the persistent challenge of momentum mismatch during intermedium topological mode transitions due to material impedance inconsistency remains. We present a 100-Gbps topological wireless communication link using integrated photonic devices that conserve valley momentum. The valley-conserved silicon topological waveguide antenna achieves a 12.2-dBi gain, constant group delay across a 30-GHz bandwidth and enables active beam steering within a 36° angular range. The complementary metal oxide semiconductor-compatible valley-conserved devices represent a major milestone in hybrid electronic-photonic-based topological wireless communications, enabling terabit-per-second backhaul communication, high throughput, and intermedium transport of information carriers, vital for the future of communication from the sixth to X generation.

Efficient Caustics Rendering via Spatial and Temporal Path Reuse

AbstractCaustics are complex optical effects caused by the light being concentrated in a small area due to reflection or refraction on surfaces with low roughness, typically under a sharp light source. Rendering caustic effects is challenging for Monte Carlo‐based approaches, due to the difficulties of sampling the specular paths. One effective solution is using the specular manifold to locate these valid specular paths. Unfortunately, it needs many iterations to find these paths, leading to a long rendering time. To address this issue, our key insight is that the specular paths tend to be similar for neighboring shading points. To this end, we propose to reuse the specular paths spatially. More specifically, we generate some specular path samples with a low sample rate and then reuse these specular path samples as the initialization for specular manifold walk among neighboring shading points. In this way, much fewer specular path‐searching iterations are performed, due to the efficient initialization close to the final solution. Furthermore, this reuse strategy can be extended for dynamic scenes in a temporal manner, such as light moving or specular geometry deformation. Our method outperforms current state‐of‐the‐art methods and can handle multiple bounces of light and various scenes.

Investigating the Role of Sport in Sustainable Environmental Development: A Case Study

Background: Sport can impact the protection of the environment and energy. Sports activities could gather people in one place, which may negatively affect the environment, such as noise pollution, antisocial behaviors, waste, air pollution, and sharp lighting. Objectives: This paper aims to investigate the role of sport in sustainable environmental development. This applied-developmental study utilized an exploratory qualitative method to collect data. Methods: The statistical population included all top managers of sports organizations (including the National Olympic Committee, Ministry of Sports, and all sports federations), specialists and experts in sport management in Iran, and some managers of the Iranian Department of Environment. Thirteen experts were selected using the purposive sampling method and snowballing technique. The semi-structured interview was used as a data collection tool. Data analysis was done with grounded theory through open, axial, and selective coding. Results: The results indicated that the pattern of sustainable environmental development based on the sport consists of 211 concepts and 26 subcategories. Categories 4, 4, 5, 8, and 4 were related to the causal factors, the fields, and domains, mediating variables, strategies, and consequences, respectively, and one category was also considered an axial phenomenon. Adequacy measure of the research process and quality of data and interpretations was approved based on credibility, transferability, dependability, confirmability, honesty, and data-derived theory criteria, including conformity, comprehensiveness, generality, and controllability. Conclusions: According to the results from the model, the sustainable environmental development based on the sport is affected by foresight, environmental values of sport, environmental requirements of the sport, green sports movement, educational and research factors, communication and promotional elements, economics, structural factors, and organizational factors, which can lead to green productivity in sports and the quality of life and well-being of citizens.

Structure and function of bark and wood chloroplasts in a drought-tolerant tree (Fraxinus ornus L.).

Leaves are the most important photosynthetic organs in most woody plants, but chloroplasts are also found in organs optimized for other functions. However, the actual photosynthetic efficiency of these chloroplasts is still unclear. We analyzed bark and wood chloroplasts of Fraxinus ornus L. saplings. Optical and spectroscopic methods were applied to stem samples and compared with leaves. A sharp light gradient was detected along the stem radial direction, with blue light mainly absorbed by the outer bark, and far-red-enriched light reaching the underlying xylem and pith. Chlorophylls were evident in the xylem rays and the pith and showed an increasing concentration gradient toward the bark. The stem photosynthetic apparatus showed features typical of acclimation to a low-light environment, such as larger grana stacks, lower chlorophyll a/b and photosystem I/II ratios compared with leaves. Despite likely receiving very few photons, wood chloroplasts were photosynthetically active and fully capable of generating a light-dependent electron transport. Our data provide a comprehensive scenario of the functional features of bark and wood chloroplasts in a woody species and suggest that stem photosynthesis is coherently optimized to the prevailing micro-environmental conditions at the bark and wood level.

Super broadband mid-infrared absorbers with ultrathin folded highly-lossy films

Super broadband optical absorbers with ultrathin films have been keenly pursued for a long time. Although highly lossy materials with sharp light attenuation have the potential to become super absorbers, a large percent of light from free space is inevitably reflected back for the distinct impedance mismatch. Here, a simple strategy, of which reducing the thickness of highly-lossy thin films to minish reflectance and simultaneously folding the ultrathin films to make light multiple pass through, is proposed to obtain super broadband mid-infrared absorbers with ultrathin films. Along this line, the absorbers were prepared by depositing Al-doped ZnO film on scaffolds consisted of alumina spherical shells, whose substrates were opaque. When the thickness of Al-doped ZnO is 43 nm and the layer number of scaffolds is three, a maximum average absorptance was achieved as 97.6% over the wavelength range from 3 to 15 μm. Applying this strategy on polished Al foil, excellent infrared camouflage performance on human-body background was demonstrated. Featured by the strong broadband optical absorption with ultrathin films, flexible access to multiple substrates and low-cost procedures, this approach has the potential in widespread applications of infrared thermal emitters and optoelectronic devices.

Namesake

Namesake Remi Recchia (bio) Named after a medieval French bishop, a transgender poet and essayist reflects on the inheritances we’re born with and those we fashion for ourselves. Click for larger view View full resolution TRANSFER OF SAINT REMI RELICS, STAINED GLASS WINDOW IN THE BASILICA OF SAINT CLOTILDE IN PARIS, FRANCE A blinding light filled the sanctuary as the two vials, once empty, filled with chrism and oil of the catechu-mens. Candles dimmed in the wake of the sharp white light. The onlookers watched the vials with disbelief, but the moribund pagan had eyes only for Remigius, archbishop of Reims. Documentation of the legend of the Baptism of the Moribund Pagan, also known as Remigius and the Holy Ampulla, does not include description of white light, a shocked congregation, or a mesmerized pagan. In truth, the sixth-century baptism of a dying man may have been a nonevent with the exception of the miraculously filled baptismal artifacts. In his early twenties, Remigius was ordained as the archbishop of Reims in 459. He is most known for converting Clovis, king of the Franks, to Christianity in 496, along with three thousand of the king’s followers. Theologians credit the canonized archbishop with the miracle performed in the Baptism of the Moribund Pagan, a [End Page 18] miracle confirmed upon the discovery of the same vials emitting an “unworldly” fragrance when his tomb was opened during the reign of Charles the Bald. _______ My own connection to France runs deep. My mom, a French professor and medievalist, went on sabbatical in 2000 in pursuit of Saint Martial, taking my dad, my twin sister, and me with her to Bretagne, or Brittany. Brittany is a rainy province in northern France, primarily dairy country, that draws much of its revenue from the local farming industry. Neither my sister nor I spoke French; it was a quick learning curve. By the end of our fourteen months there—at the end of which we would be eight years old—we would be fluent. After spending our seventh birthday in Paris, we arrived in Brittany for what would be my sister’s and my second-grade year. My parents had rented what had once been an old chateau called Tréhorenteuc, or Tregarantec, which was now a dairy farm, except we weren’t staying in the chateau proper—we lived in a section of the property that was just outside the big house. On the phone years later, my mom describes the grand chateau as shaped like a huge semicircle, or something U-shaped. Our part of the property was at the end of one of the hedges of the semicircle. Our own French haven. Tregarantec was in the small village of Mellionec. Mellionec’s geographical landscape is similar to rural Ohio or Michigan in soft rain with cows and abandoned wells and tractors. Tregarantec was a seventeenth-century chateau; my mom tells me now that it was rumored to have been a gift to one of Louis XIV’s mistresses. Our living space had two floors with the kitchen on the first floor and one or two bedrooms on the second floor. A clothesline ran through my parents’ bedroom, safe inside because it rained so frequently in Brittany. The kitchen was a claustrophobia of walls and cupboards. My sister and I went to a Catholic school in the nearby town of Rostrenen called L’École Notre Dame. Though Catholic in name, it was run fairly secularly according to my mom, and it cost a mere ten euros, or eleven US dollars, a month. Our dad drove us down the long dirt driveway from Tregarantec each day. We had to time our arrival and departure perfectly so as not to get stuck behind the cows on their way to the milking parlor at regular intervals throughout the day. Sometimes if we were running late, we had to duck beneath the electric wire to get in the car. It was my favorite game. I do not think I can offer anything new on the trope of foreboding nuns at Catholic school, but I will try. I remember that the nuns did not preside over...

First Speleological and Biological Characterization of a Submerged Cave of the Tremiti Archipelago Geomorphosite (Adriatic Sea)

The Tremiti Islands Archipelago is located in the Central-Southern Adriatic Sea and is characterized by a strong karst activity. Due to their landscape, geological, hydrological, archaeological, and historical value, Tremiti Islands are considered a geomorphosite. We carried out a preliminary, non-destructive survey by studying the speleological and biological features of the submerged sea cave Elle, located at Cala Sorrentino (Capraia Island), representing an EU Natura 2000 Priority Habitat. Topographic (perimeter length, width, height, GPS location, depth) and hydrological parameters (temperature, dissolved oxygen, pH, irradiance, water movement) were measured and its map was produced, based on morphological measurements and biological evidence. Species composition and biotic cover were investigated by image analysis. The benthic community was dominated by poriferans, together with remarkable assemblages of scleractinians and polychaete serpulids and clearly reflected the sharp light and hydrological gradients from the entrance to the cave bottom. Furthermore, different phases were hypothesized for the genesis of the cave during sea regression and flooding periods. To be signaled is the record of Petrobiona massiliana, a sponge was protected under both Barcelona and Bern Convention and of some individuals of polychaete Serpulinae, which are still under description.

Black Sea Mnemiopsis leidyi (Ctenophora) adult locomotion and light-induced behavior in laboratory experiments

The capacity of Ctenophores to sense light is indicated by comparative morphology and genomics data, but the relevant behavioral responses of the animals to light stimulus have not been studied yet. We developed the design of a laboratory experiment to reveal the light-induced behavior of adult Mnemiopsis leidyi from the Black Sea and identified criteria for its evaluation. Average swimming speed up to ~6–7 mm s−1 can be considered specific for the M. leidyi adults under rest or active feeding. Ctenophore reacts to a sharp light rise as an external stimulus, briefly increasing the rate several times (up to 40 mm sec−1). Analysis of motion vectors revealed no directional movement from the light source or towards it. Maximum and average rates decrease significantly for two minutes after the light is turned on, and speeds return to the original values within an hour. Small animals are more active than large ones. The mean motion rates of small comb jellies (<60 mm) were 0.7 ± 0.84 mm s−1 and 0.18 ± 0.19 mm s−1 - for large animals (>80 mm) when averaging the data for the entire observation period (from February to June).

Implication of color of sensitizing dyes on transparency and efficiency of transparent dye-sensitized solar cells

Dye-sensitized solar cells (DSSCs) are one of the potential candidates for the fabrication of colourful and see-through solar cells for energy harvesting esthetic windows. However, a trade-off between transparency and power conversion efficiency (PCE) has to be tackled amicably to realize the solar cells with good PCE and transparency. Judicious selection of dyes to bypass the light absorption in the high eye-sensitivity region (500–600 nm) is one of the plausible solutions. This was demonstrated utilizing yellow (D-131) and red (N-719) commercial dyes along with newly developed blue (SQ-138) and green coloured (SQ-140) dyes with intense and sharp light absorption mainly in the far-red to near-infrared (NIR) wavelength region. Transparent DSSCs fabricated using the most commonly used red-coloured dye N-719 although exhibited an increase in the PCE from 2.9% to 5.3% upon increasing the thickness of the transparent TiO2 layer from 4 μm to 10 μm but resulted in a serious loss in the average visible transparency (AVT) from 58.6% to 7.3% making the DSSC non-transparent. Contrary to this, under similar thickness variations, dyes D-131, SQ-138 and SQ-140 exhibiting very high AVT of >70% maintained the AVT > 40%, which is necessary for good visual perception.

Dual-mode optical thermometry based on Bi3+/Eu3+ co-activated BaGd2O4 phosphor with high sensitivity and signal discriminability

A series of BaGd2O4:Bi3+,Eu3+ phosphors with dual-emitting centers were prepared by high-temperature solid-state method. X-ray diffraction (XRD), scanning electron microscope (SEM), energy dispersive spectroscopy (EDS), fluorescence spectroscopy, lifetime decay curve and variable temperature emission spectroscopy were used to systematically study the structure, luminescence performance and temperature characteristics. Under ultraviolet (UV) excitation, the BaGd2O4:Bi3+,Eu3+ phosphor showed a broad-band emission in the blue region corresponding to transitions of Bi3+ ions and the sharp red light emission corresponding to Eu3+ ions. The Bi3+ and Eu3+ ion emission peaks were well-separated, which meets a prerequisite for efficient temperature signal resolution measurement. The fluorescence intensity ratio (FIR) technique was used to measure the different temperature response characteristics between Bi3+ blue emission and Eu3+ red emission. When the temperature varies from 293 K to 473 K, the relative temperature sensitivity (Sr) of BaGd2O4:Bi3+,Eu3+ phosphors is obtained, was determined as 1.0182%K−1. In addition to calculating the relative sensitivity by FIR technology, we can also obtain the value of Sr through experiments and formulas related to the decay life, and found to be 1.0651%K−1. Therefore, BaGd2O4: Bi3+,Eu3+ phosphor is an excellent non-contact optical temperature measurement material.

Luminescence investigation of a novel red-emitting Sr3NaSbO6:Eu3+ phosphor

A new red-emitting phosphor Sr3NaSbO6:Eu3+ with different Eu3+ contents has been prepared by a solid-state method. The crystal structure, photoluminescence properties and concentration quenching of Sr3NaSbO6:Eu3+ phosphors were studied in detail. Under excitation at 285 nm, a sharp red light was observed originating from the 5D0→(7F1, 7F2)transition of the Eu3+. The concentration quenching mechanism has been investigated, and demonstrated to involve a dipole-dipole interaction. We also probed the decay lifetime and calculated the CIE coordinates, which we found to lie in the red region. The results propose Sr3NaSbO6:Eu3+ phosphor as a promising red light-emitting material for UV- pumped white light-emitting diodes.

Modulation of red-light emission from carbon quantum dots in acid-based environment and the detection of chromium (Ⅲ) ions

In this study, the carbon quantum dots, which can emit sharp red light (R-CQDs) under optical excitation, were synthesized via simple heat treatment of wine lees. The features of the photoluminescence (PL) emission from R-CQDs in solutions with different pH values and with metal ions were examined. The intensity of the PL emission from R-CQDs depends sensitively on the pH values of the solutions with the R-CQDs. Interestingly, the pH-response of the PL intensity is reversible and can be enhanced linearly in the pH value range from 4 to 12, indicating that the R-CQDs can be applied for the pH sensor. Furthermore, the quench of the PL emission from R-CQDs can be observed when adding chromium (III) ions into the solution with R-CQDs. This effect can be utilized for selective and quick detection of chromium (III) ions in solutions simply via the standard PL measurement. The interesting and important findings from this work can be applied to explore more practical applications of the CQDs prepared cheaply and easily.

Ultrapure green light emission in one-dimensional hybrid lead perovskites: achieving recommendation 2020 standard

New 1D halide of [TMPDA]2Pb3Br10 displays a sharp green light emission at 526 nm with FWHM of 25 nm, PLQY of 71.95% and color purity of 91.1%, which achieves the Rec. 2020 standard, and represents the purest green light emitting 1D halide up to date.

From environmental degradation to the waste economy of postcolonial desire: Ecocritical footprints in Touki Bouki and Hyenas

There is a tendency, among Mambety critics, to overemphasize his formal innovations and parodic contents, his virtuosic collages and subtle nods to auteur and genre cinema, at the expense of a sustained engagement with the acute environmental sensibility running through all his films, notably at the start of a film career that is contemporaneous with the Great Sahel Drought of the late 1960s and early 1970s. This article focuses on the ecocritical edge neatly blended into the narrative structures and visual aesthetics of the classic Touki Bouki and Hyenas. The point is, through a minute analysis of the tropes and metaphors of lack, scarcity and abundance, to cast a sharp light on the deep-ecological angst informing Mambety’s cinematic gaze.

The luminescent emission and quantum optical efficiency of Cd1-xSrxSe QDs developed via ions exchange approach for multicolor-lasing materials and LED applications

A new family of Cd1-xSrxSe semiconductor quantum dot was synthesized using ions exchange method. The TEM measurement inspected that the Cd1-xSrxSe crystals have spherical particles with mean sizes in the range of 3.1 nm to 7.8 nm reliant to the quantity of Sr-dopant assimilated in CdSe. The optical absorbance spectra indicated that the Sr-dopant created sublevels within the bandgap of the CdSe, which caused a red shift displacement of the spectral curves. The luminescent emission spectral bands showed an improvement of the intensity of the luminescent emission spectra and narrowing of their bandwidth. It is also showed that the bandgap lowered from 3.62 eV to 2.74 eV. The Sr-dopant enhanced the quantum yield from 23 % to 87 %. The intensive, sharp luminescent emission light emerged from the developed Cd1-xSrxSe QD crystals with quantum efficiency of 87 %, pave the way for a novel family of QDs capable to be employed for lasing and multicolor light emitting diodes application.

The luminescence and quantum optical efficiency characteristics of Lu-doped CdSe QDs prepared by ethylglycol assisted solvothermal approach for laser diode and multicolor display window applications

A highly crystalline Cd 1-x Lu x Se semiconducting quantum dots were concocted using ethylglycol assisted solvothermal route. The XRD revealed that the Cd 1-x Lu x Se QDs exhibiting a zinc blende cubic structure. The TEM measurement disclosed that the Cd 1-x Lu x Se nanocrystals have nanoparticle like sphere with average sizes in the range of 2.7 nm to 9.1 nm as the amount of Lu-dopant incorporated in CdSe was increased. The absorbance spectrum confirmed that the Lu-dopant establish sublevels inside the CdSe bandgap, which prompted a decrease of bandgap from 3.1 eV to 2.75 eV. An enhancement of the emission spectra intensities and reduction of the spectral bandwidth was successfully achieved. The Lu-dopant enhanced the quantum yield from 18 % to 81 %. The intensive and sharp luminescent emission light emerged from the Cd 1-x Lu x Se QDs with quantum efficiency of 81 %, pave the way for a novel family of QDs capable to be employed for laser diodes and multicolor display windows.