Police Investigate Aggravated Burglary and search for missing vehicle

first_imgFacebook Twitter Google+LinkedInPinterestWhatsApp Facebook Twitter Google+LinkedInPinterestWhatsAppTurks and Caicos, April 10, 2017 – Providenciales – Detectives are searching and seeking the assistance of the public in locating a 2008 Silver Nissan Skyline car, Licence plate unknown that was stolen during an Aggravated Burglary incident that occurred on Friday 7th April 2017 in Wheeland Settlement of Providenciales.Police responded to the Belglade Gardens area also known as Phase one where the complainant  was met and told officers that around 8:55PM he was at home when three masked men dressed in dark clothing came into his home with guns and assaulted him. The culprits took his Iphone, Xbox, a Jamaican Passport and the vehicle mentioned above. He describe the men as being slim built 5 feet 8 inches in height, and the other thicker in size.  The victim was taken to the Cheshire Hall Medical for his injuries. Investigations are ongoing.Anyone who may have witnessed this incident or have information that can assist with investigation can contact the Chalk Sound Police Station at 338-5901. To remain anonymous, call Crime Stoppers at 1- 800 8477 or use the Crime Stoppers online reporting page: www.crimestoppers.tc.Press Release: RTCIPF Related Items:last_img read more

115 people arrested in San Diego and Imperial counties after ICE operation

first_img115 people arrested in San Diego and Imperial counties after ICE operation 00:00 00:00 spaceplay / pause qunload | stop ffullscreenshift + ←→slower / faster ↑↓volume mmute ←→seek  . seek to previous 12… 6 seek to 10%, 20% … 60% XColor SettingsAaAaAaAaTextBackgroundOpacity SettingsTextOpaqueSemi-TransparentBackgroundSemi-TransparentOpaqueTransparentFont SettingsSize||TypeSerif MonospaceSerifSans Serif MonospaceSans SerifCasualCursiveSmallCapsResetSave SettingsSAN DIEGO (KUSI) — U.S. Immigration and Customs Enforcement (ICE) deportation officers arrested 115 individuals for violating federal immigration laws in the San Diego and Imperial counties during a three-day targeted enforcement operation that ended Thursday.Fifty of the immigration violators arrested were convicted criminals and seven others illegally re-entered the U.S. after removal. All but seven of the arrests took place in San Diego County. Seven others had re-entered the United States after being removed on the basis of an Immigration Judge’s final order of removal.Depending on the alien’s criminal history, an alien who illegally reenters the United States, after having been previously removed, has committed a felony punishable by up to 20 years in federal prison.“This week’s operation targeted public safety threats, such as convicted criminal aliens, individuals with final orders of removal, those who illegally re-entered the country after being removed, and individuals who have otherwise violated our nation’s immigration law,” said Greg Archambeault, field office director for ICE Enforcement and Removal Operations (ERO) in San Diego. “Operations like this reflect the vital work ERO officers do every day to protect the nation, uphold public safety and protect the integrity of our immigration laws and border controls.  We will continue to conduct similar operations, while seeking to ultimately deport at-large criminal targets and other immigration fugitives who pose a threat to public safety.”The arrests include:A 43-year-old Mexican national and Center Street Locos gang member in Oceanside, California, who had previously been removed from the U.S. on four prior occasions. He has multiple criminal convictions, including grand theft, controlled substance for sale and driving under the influence.A 55-year-old citizen of Kazakhstan who is wanted by authorities in Kazakhstan for alleged tax evasion and embezzlement. He was taken into ICE custody at his Oceanside residence Tuesday pursuant to a “Red Notice” arrest warrant issued by Interpol in September.A 52-year-old citizen of Mexico sentenced to 30-months in federal prison in 2009 after being convicted of illegal re-entry after deportation. He has three criminal convictions for spousal abuse, including battery, inflicting injury and threatening to terrorize, and was ordered removed by an immigration judge in 1998.  He had previously been removed from the U.S. to Mexico on 10 prior occasions.Four of the individuals arrested during this operation will face federal criminal prosecution for illegal re-entry after deportation. The arrestees who are not being federally prosecuted will be processed administratively for removal from the United States. Those who have outstanding orders of removal, or who returned to the United States illegally after being deported, are subject to immediate removal from the country. The remaining individuals are in ICE custody awaiting a hearing before an immigration judge, or pending travel arrangements for removal in the near future.Of the public safety targets who remain at large, those believed to be residing in or around the San Diego area include:A citizen of Mexico convicted of statutory rape, sex with a minor in 2012. He was previously removed from the United States in 2003.A citizen of Mexico convicted of domestic violence in 2010 and known associate of the “ESD” street gang. He was last removed from the United States in 2007 and illegally re-entered on an unknown date.While the vast majorities of cities in America do cooperate with ICE, state laws in California force ICE to focus additional resources to conduct at-large arrest in the community, putting officers, the general public and aliens at greater risk and increase the incidents of collateral arrests.These arrests were driven by leads developed by the local field office in conjunction with the Pacific Enforcement Response Center and the National Criminal Alien Targeting Center. ICE focuses its enforcement resources on individuals who pose a threat to national security, public safety and border security.However, ICE does not exempt classes or categories of removable aliens from potential enforcement. All of those in violation of the immigration laws may be subject to immigration arrest, detention and, if found removable by final order, removal from the United States. ICE does not conduct sweeps or raids that arrest aliens indiscriminately. KUSI Newsroom Posted: March 16, 2018 Categories: Local San Diego News FacebookTwittercenter_img March 16, 2018 Updated: 6:19 PM KUSI Newsroom, last_img read more

Lightning kills woman in Sunamganj

first_imgLightning strikeA female farmer was killed after being hit by a thunderbolt at a haor in Purangaon village of Bishwambharpur upazila, Sunamganj on Tuesday morning.The deceased was identified as Shahara Banu, wife of late Hazrat Ali of the village in Dakhshin Badaghat union, reports UNB.Family sources said the thunderbolt hit Shahara while she went to the haor for bringing cattle, leaving her dead on the spot.Meanwhile, three people were injured in another incident of lightning at Hatamar village in Fenarbak union of Jamalganj upazila in the morning.last_img read more

Amid Harvey Floods Chief Acevedo Worries How Many Bodies

first_img@HoustonISDHFD helps with rescues during Harvey flooding.Crews overwhelmed by thousands of rescue calls during one of the heaviest downpours in U.S. history have had little time to search for other potential victims, but officials acknowledge the grim reality that fatalities linked to Harvey could soar once the devastating floodwaters recede from one of America’s most sprawling metropolitan centers.More than three days after the storm ravaged the Texas coastline as a Category 4 hurricane, authorities had confirmed only three deaths — including a woman killed Monday when heavy rains dislodged a large oak tree onto her trailer home in the small town of Porter. But unconfirmed reports of others missing or presumed dead were growing.“We know in these kind of events that, sadly, the death toll goes up historically,” Houston police Chief Art Acevedo told The Associated Press. “I’m really worried about how many bodies we’re going to find.”One Houston woman said Monday that she presumes six members of a family, including four of her grandchildren, died after their van sank into Greens Bayou in East Houston, though Houston emergency officials couldn’t confirm the deaths. Virginia Saldivar told The Associated Press her brother-in-law was driving the van Sunday when a strong current took the vehicle over a bridge and into the bayou. The driver was able to get out and urged the children to escape through the back door, Saldivar said, but they could not.“I’m just hoping we find the bodies,” Saldivar said.And a spokeswoman for a Houston hotel says one of its employees disappeared while helping about 100 guests and workers evacuate the building amid rising floodwaters.The disaster is unfolding on an epic scale, with the nation’s fourth-largest city mostly paralyzed by the storm that has parked itself over the Gulf Coast. With nearly 2 more feet (61 centimeters) of rain expected on top of the 30-plus inches (76 centimeters) in some places, authorities worried the worst might be yet to come.The Houston metro area covers about 10,000 square miles (25,900 sq. kilometers). It’s crisscrossed by about 1,700 miles (2,700 kilometers) of channels, creeks and bayous that drain into the Gulf of Mexico, about 50 miles (80 kilometers) to the southeast from downtown.The storm is generating an amount of rain that would normally be seen only once in more than 1,000 years, said Edmond Russo, a deputy district engineer for the Army Corps of Engineers, which was concerned that floodwater would spill around a pair of 70-year-old reservoir dams that protect downtown Houston.Rescuers meanwhile continued plucking people from inundated neighborhoods. Mayor Sylvester Turner put the number by police at more than 3,000. The Coast Guard said it also had rescued more than 3,000 by boat and air and was taking more than 1,000 calls per hour.Chris Thorn was among the many volunteers still helping with the mass evacuation that began Sunday. He drove with a buddy from the Dallas area with their flat-bottom hunting boat to pull strangers out of the water.“I couldn’t sit at home and watch it on TV and do nothing since I have a boat and all the tools to help,” he said.A mandatory evacuation was ordered for the low-lying Houston suburb of Dickinson, home to 20,000. Police cited the city’s fragile infrastructure in the floods, limited working utilities and concern about the weather forecast.In Houston, questions continued to swirl about why the mayor did not issue a similar evacuation order.Turner has repeatedly defended the decision and did so again Monday, insisting that a mass evacuation of millions of people by car was a greater risk than enduring the storm.“Both the county judge and I sat down together and decided that we were not in direct path of the storm, of the hurricane, and the safest thing to do was for people to stay put, make the necessary preparations. I have no doubt that the decision we made was the right decision.”He added, “Can you imagine if millions of people had left the city of Houston and then tried to come back in right now?”By Monday night, 7,000 people had arrived at the city’s largest shelter set up inside the George R. Brown Convention Center — which originally had an estimated capacity of 5,000.Red Cross spokesman Lloyd Ziel said that volunteers made more space inside the center, which also was used to house Hurricane Katrina refugees from New Orleans in 2005, in part by pushing some cots closer together. A shortage of cots means some people will have to sleep on chairs or the floor.The center settled down at night, after an occasionally chaotic day that saw thousands of evacuees arrive in the pouring rain. Officers and volunteers at times rushed to attend to those with medical needs.At the Addicks and Barker reservoirs, the Army Corps started releasing water Monday because water levels were climbing at a rate of more than 6 inches (15 centimeters) per hour, Corps spokesman Jay Townsend said.The move was supposed to help shield the business district from floodwaters, but it also risked flooding thousands more homes in nearby subdivisions. Built after devastating floods in 1929 and 1935, the reservoirs were designed to hold water until it can be released downstream at a controlled rate.In the Cypress Forest Estates neighborhood in northern Harris County, people called for help from inside homes as water from a nearby creek rose to their eaves. A steady procession of rescue boats floated into the area.Harvey increased slightly in strength Monday as it drifted back over the warm Gulf, according to the National Hurricane Center.Forecasters expect the system to stay over water with 45 mph (72 kph) winds for 36 hours and then head back inland east of Houston sometime Wednesday. The system will then head north and lose its tropical strength.Before then, up to 20 more inches (51 centimeters) of rain could fall, National Weather Service Director Louis Uccellini said Monday.That means the flooding will get worse in the days ahead and the floodwaters will be slow to recede once Harvey finally moves on, the weather service said.Sometime Tuesday or early Wednesday, parts of the Houston region will probably break the nearly 40-year-old U.S. record for the biggest rainfall from a tropical system — 48 inches (120 centimeters) — set by Tropical Storm Amelia in 1978 in Texas, meteorologists said.The amount of water in Houston was so unprecedented that the weather service on Wednesday had to update the color charts on its official rainfall maps to indicate the heavier totals.In Louisiana, the images of the devastation in Houston stirred painful memories for many Hurricane Katrina survivors.“It really evoked a lot of emotions and heartbreak for the people who are going through that now in Houston,” Ray Gratia said as he picked up sandbags for his New Orleans home, which flooded during the 2005 hurricane.In Washington, President Donald Trump’s administration assured Congress that the $3 billion balance in the Federal Emergency Management Agency’s disaster fund was enough to handle immediate needs, such as debris removal and temporary shelter for displaced residents.The White House said Monday night that the president and first lady will visit Corpus Christi and Austin on Tuesday. They will receive briefings on the relief efforts by local leaders and organizations.Harvey was the fiercest hurricane to hit the U.S. in 13 years and the strongest to strike Texas since 1961’s Hurricane Carla, the most powerful Texas hurricane on record. Sharelast_img read more

China Deletes Nearly 10000 Social Media Accounts in Latest Crackdown

first_imgDeleted accounts included those of “a popular talk show celebrity, an entertainment blogger who shared film footage, online influencers commenting on social issues, and bloggers writing extensively on ethnicity,” according to the Hong Kong-based South China Morning Post.“Some spread politically harmful information, maliciously distorted party or state history, slandered heroes, or discredited the country’s image. Some created rumors, spread fake information, generated clickbait…disrupting the normal social order,” the CAC statement said. It added that other deleted accounts had participated in “malicious marketing,” extortion, or copyright infringement, while others had spread vulgar content, “challenging the moral bottom line and harming the healthy growth of the majority of young people.”China has severely ramped up media policing since President Xi Jinping took office in 2012, and is increasingly concerned that airwaves and chatrooms should only be filled with government-friendly, “positive” content. Western social media sites including Google, Facebook, and Twitter are inaccessible in mainland China. Only content that passes strict censorship reviews is supposed to be aired or screened.The crackdowns have sometimes been unintentionally absurd or hilarious. In 2016, authorities banned live-streamers from eating bananas in an “erotic” fashion while on camera. Last summer, they famously banned Western teen idol Justin Bieber from performing on the mainland. Authorities cited unspecified bad behavior on and off stage that they said made him an unsavory person who would prevent China from “purifying” and “maintaining order” in its performing arts scene. And in January, authorities asked TV shows to keep off air performers displaying tattoos or anything related to hip-hop music or subcultures.The CAC called meetings to issue “serious warnings” to managers of Sina Weibo and Tencent’s WeChat, it said. The companies had been chastised for “irresponsible and neglectful management” of the social media space, which had “allowed wild growth and caused all kinds of chaos.” Popular on Variety ×Actors Reveal Their Favorite Disney PrincessesSeveral actors, like Daisy Ridley, Awkwafina, Jeff Goldblum and Gina Rodriguez, reveal their favorite Disney princesses. Rapunzel, Mulan, Ariel,Tiana, Sleeping Beauty and Jasmine all got some love from the Disney stars.More VideosVolume 0%Press shift question mark to access a list of keyboard shortcutsKeyboard Shortcutsplay/pauseincrease volumedecrease volumeseek forwardsseek backwardstoggle captionstoggle fullscreenmute/unmuteseek to %SPACE↑↓→←cfm0-9Next UpJennifer Lopez Shares How She Became a Mogul04:350.5x1x1.25×1.5x2xLive00:0002:1502:15 China’s Internet watchdog has scrubbed the country’s already highly censored web of nearly 10,000 social media accounts in the past three weeks. It is the ruling Communist Party’s latest move to clamp down on freedom of expression. The cleanup began Oct. 20, the Cyberspace Administration of China said in a statement posted late Monday to its official website. The removals follows a similar purge in June that took down scores of entertainment news media accounts, among others. More than 9,800 accounts were removed from Chinese social media platforms such WeChat and Weibo, the country’s Twitter equivalent, as well as from its Google-like search engine Baidu. The sweep also included leading private-sector news aggregators Toutiao and Sohu.  Sina Weibo in turn said on its official account that it had “seriously accepted” the need to rectify its management procedures, and would “implement corrective actions” that focused on curbing pornographic and “politically harmful” content. It issued an 11-point list describing what now constitutes such content, including posts that “endanger national sovereignty and territorial integrity,” “spread rumors, disrupt social order, and undermine social stability,” or “distort, vilify or defame…heroic martyrs.” In a series of posts earlier this week, Weibo also publicly named a number of popular accounts that had since been deleted, including some with nearly 5 million followers. It explained that others had been temporarily suspended for content such as a “beautiful male butt contest.”Disgruntled users and fans took to Weibo to express their dismay over missing accounts, though it appeared that many negative messages were themselves soon censored. “Wow, they can really just totally wipe out a person in the blink of an eye. This round of purification is just too horrible,” one wrote Wednesday. “Even ‘big V’ online influencers are just sacrificial lambs – as the authorities sharpen their knives, everyone is in danger.” Another asked: “This person was only talking about economics — that’s not okay either?”Bemoaning the loss of a popular account, one user wrote: “If even this account is closed, should we expect to be watching only ‘model operas’ in the coming years?” That is a reference to the eight politically approved stories that were the only ones permitted on screen or stage during the tumultuous years of the 1966-76 Cultural Revolution.last_img read more

Efficient and stable emission of warm white light from leadfree halide double

first_img White light emission from a single emitter layer is of interest in lighting applications due to its simplicity compared to multiple emitters. Typically, broadband and white light emissions originate from self-trapped excitons (STEs) existing in semiconductors with localized carriers and a soft lattice. The authors focused on the double perovskite Cs2AgInCl6 as a promising material that emits warm white light due to its broad spectrum and all-inorganic, lead-free nature. The study optimized the alloy to form Cs2(Ag0.6Na0.4)InCl6 with a small percentage of bismuth doping to emit warm white light with increased quantum efficiency for more than 1000 hours. Materials for lighting applications can be defined as those emitting a “warm” white light for indoor applications and “cold” white light that approximates the visible region of the solar spectrum. In the study, Luo et al first sought to understand the origins of broadband emissions in Cs2AgInCl6 using mathematical modeling and computational studies to relax the lattice and represent self-trapped excitons (STEs) to investigate exciton-phonon coupling. Such systems will be fundamental to engineer the next generation of energy-efficient and cost-effective lighting and display technologies. A self-trapped exciton (STE) is defined as a bound electron-hole pair carrier that can dramatically enhance luminescence, energy transport and lattice defect formation in the crystal. The researchers found that STEs in the double perovskite Cs2AgInCl6, arose from strong Jahn-Teller distortion of the integral AgCl6 octahedron complex. The trapped excitons had a similar orbital character to the free exciton, indicating parity-forbidden transition (arising due to disruption of the centre of symmetry). The theoretical analysis showed an extremely low photoluminescence quantum yield (PLQY) for pure Cs2AgInCl6. To enhance the PLQY for practical applications as broadband materials, the system had to be modified, specifically by breaking parity-forbidden transition to manipulate the symmetry of the STE wavefunction. Explore further Lighting it up: A new non-toxic, cheap, and stable blue photoluminescent material Computational studies of self-trapped excitons (STEs) in Cs2AgInCl6. a) GW band structure of the double perovskite crystal (Cs2AgInCl6). The orbital characters and the free-exciton wavefunction are plotted as a fat-band structure. The green, blue, cyan and red colors denote the Cl 3p, Ag 4d, In 5s and Ag 5s orbitals. The magenta circles represent the lowest free-exciton amplitude. b) STE in Cs2AgInCl6, Cs atoms are omitted for clarity. The cyan and magenta isosurfaces represent the electron and hole orbital densities respectively. The electron state (red dashed circle) is extended and the hole state (black dashed circle) is compact, consistent with the small effective mass of the conduction band seen in (a). The inset shows the Jahn-Teller distortion of the AgCl6 octahedron. The hole isosurface is obvious and electron isosurface invisible due to its small density. c) Configuration coordinate diagram for the STE formation; Est, Ed and EPL are self-trapping, lattice-deformation and emission energies. d) The calculated photoluminescence spectrum compared with the experimental result. The calculated curve was shifted to align its maximum with that of the experimentally measured curve for better comparison. Credit: Nature, doi: https://doi.org/10.1038/s41586-018-0691-0 White light emission from Cs2Ag1−xNaxInCl6. a) Luminosity function (dashed line) and photoluminescence spectra (solid lines) of Cs2Ag0.6Na0.4InCl6 measured at different temperatures from 233 K to 343 K. b) Photoluminescence stability of Cs2Ag0.60Na0.40InCl6 against continuous heating on a hotplate, measured after cooling to room temperature. c) Operational stability of Cs2Ag0.6Na0.4InCl6 down-conversion devices measured in air without any encapsulation. The boxplot showed the results for the different samples measured separately with the box edges representing quartiles and band in the box representing the mean and maximum data. d) XRD patterns of a Cs2Ag0.6Na0.4InCl6 film (black line) and powder (red line). The inset shows a 300 nm thick quartz substrate and 500 nm thick Cs2Ag0.6Na0.4InCl6 films under 254 nm UV illumination. Credit: Nature, doi: https://doi.org/10.1038/s41586-018-0691-0. Since lattice mismatch between the two perovskites (Cs2AgInCl6 andCs2NaInCl6) was very low (0.3 percent) the scientists anticipated Na+ incorporation would occur without detrimental defects or phase separation. For the synthesis, CsCl, NaCl, AgCl and InCl3 precursors were mixed into an HCl solution in a hydrothermal autoclave. The mixture was heated for a defined period of time and cooled down to result in a final white precipitate product (90 percent yield). The pure double perovskite phase was confirmed using X-ray diffraction patterns (XRD) of a series of product compositions. The results agreed with plasma optical emission spectrometry (ICP-OES). The results were also in agreement with similar alloying experiments that were previously conducted with lithium (Li). The study thus suggested a general trend for alkali-metal-induced photoluminescent enhancement in double perovskites. Photoluminescence spectra were recorded for a series of product powders by varying the temperature of the measurements. The authors optimized the Na content alongside bismuth (Bi3+) doping to improve the crystal quality and slow cooling to obtain the highest PLQY (85 ± 5 percent) recorded thus far for white-light-emitting materials to form the optimally alloyed Cs2Ag0.6Na0.4InCl6 in the study. More information: Jiajun Luo et al. Efficient and stable emission of warm-white light from lead-free halide double perovskites, Nature (2018). DOI: 10.1038/s41586-018-0691-0 Yiru Sun et al. Management of singlet and triplet excitons for efficient white organic light-emitting devices, Nature (2006). DOI: 10.1038/nature04645 Zewen Xiao et al. Searching for promising new perovskite-based photovoltaic absorbers: the importance of electronic dimensionality, Materials Horizons (2016). DOI: 10.1039/C6MH00519E Citation: Efficient and stable emission of warm white light from lead-free halide double perovskites (2018, November 19) retrieved 18 August 2019 from https://phys.org/news/2018-11-efficient-stable-emission-white-lead-free.html Characterization of Cs2AgxNa1−xInCl6 with different Na content. All samples were doped using a small amount of (0.04 percent) Bi and the composition determined using ICP-OES. a) XRD patterns of Cs2AgxNa1−xInCl6 powders with different Na content were obtained. The Asterix marks the (III) diffraction peak, θ diffraction angle and au – arbitrary units. b) Optical absorption (solid lines) and photoluminescence (dashed lines) spectra of pure Cs2AgInCl6 and Cs2Ag0.6Na0.4InCl6. c) Activation energy and PLQY of Cs2AgxNa1−xInCl6 powder vs. Na content. The dashed lines guide the eye. d) Excitation spectra of photoluminescence measured at different wavelengths. e) Emission intensity vs. excitation power for Cs2Ag0.6Na0.4InCl6. f) Transient absorption spectra for Cs2Ag0.6Na0.4InCl6 (laser pulse of 325 nm), ∆ A/A is optical density. The irregular peaks located at ~650 nm is from frequency doubling of the pumping light. Credit: Nature, doi: https://doi.org/10.1038/s41586-018-0691-0. A practical approach to achieve this was via partial substitution of Ag with an element that could sustain the double perovskite structure. The substitute required a distinctively different electronic configuration to Ag, such as a group-IA element or alkali metal. The scientists therefore explored alloying Na into Cs2AgInCl6 to form pure Cs2NaInCl6, which demonstrated broadband emission on substitution but with very low efficiency due to strong phonon emission, requiring optimization of the Na content in the complex. Photoluminescence excitation (PLE) spectra confirmed STE origin of the white emission to experimentally confirm the calculated time-scale of exciton self-trapping. The Na perovskite (Cs2Ag0.6Na0.4InCl6) exhibited linear dependence on the photoexcitation power. Additional theoretical tests were done to understand how PLQY varied as a function of the Na content. As the Na content increased, the transition dipole moment increased and then decreased to support the composition-dependent PLQY observed in the study. The electron wavefunction of the STEs was also compared before and after alloying with Na. Incorporating Na broke the inversion symmetry of the Cs2AgInCl6lattice, changing the electron wavefunction at the Ag site from symmetric to asymmetric. Two factors contributed to the decrease in PLQY on further increase of the Na content. The first was orbital overlap between electrons and holes of the STEs upon increased Na content. The second reason for the observed decrease in PLQY with increased Na was due to increased non-radiative loss in the Na-rich alloy. The scientists then developed a white light emitting diode (LED) by directly pressing the Na perovskite powders on to a commercial ultraviolet LED chip, without epoxy or silica encapsulation for protection. With the contribution from the blue light of the UV LED chip the device demonstrated a color temperature of 4,054 K to fulfill requirements for indoor lighting. When the white LED was operated for more than 1000 hour in air, negligible degradation was observed. The outstanding photometric performance combined with easy manufacture indicated promise for white-phosphor lighting applications. In this way, the scientists presented a new strategy to produce broadband emission associated with the STEs for single-material based white-light electroluminescence, allowing prototype double-perovskite based electroluminescence device formation. To increase electroluminescence performance in the future, further research should focus on optimizing the emitting-layer quality of the Cs2Ag0.6Na0.4InCl6 films. The study showed that alloying Na into Cs2AgIn Cl6 broke parity-forbidden transition as anticipated to reduce its electronic dimensionality and enable efficient white light emission via STEs.The white light emitting material also demonstrated low cost manufacture and exceptional stability as a promising solid-state lighting platform. The authors believe that such halide double perovskites hold great possibility for applications in display and lighting after further study to realize their full potential. The results will stimulate research on single-emitter-based white-light-emitting phosphors and diodes to generate the next-generation of lighting and display technologies. One-fifth of global electricity consumption is based on lighting; efficient and stable white-light emission with single materials is ideal for applications. Photon emission that covers the entire visible spectrum is, however, difficult to attain with a single material. Metal halide perovskites, for instance, have outstanding emission properties but contain lead, and therefore yield unsatisfactory stability. A new report published by Jiajun Luo and co-workers details a lead-free double perovskite that exhibited stable and efficient white light emission. In its mechanism of action, the material produced self-trapped excitons (STEs) due to Jahn-Teller distortion of the AgCl6 octahedron in the excited state of the complex, observed when investigating exciton-phonon coupling in the crystal lattice. The results are now published in Nature. A key challenge for lighting applications is the parameter of emission stability. The Cs2Ag0.6Na0.4InCl6perovskite showed stable emission in the study with little emission degradation. When the powder was annealed to a hotplate, only minimal photoluminescence decay of the white emission was observed, the authors proposed that the observations may be due to strongly bound excitons and a nearly defect-free lattice that prevented photoluminescence quenching while resisting thermal stress. Schematically visualizing the phonon band structure of Cs2AgInCl6 and the zone-center Jahn-Teller phonon mode (inset). The Jahn-Teller phonon mode coupled to the photoexcited excitons were responsible in the formation of self-trapped excitons in the Cs2AgInCl6 complex. Credit: Nature, doi: https://doi.org/10.1038/s41586-018-0691-0 Journal information: Nature © 2018 Science X Network Mechanistic investigation of PLQY in Cs2Ag1−xNaxInCl6. a) Transition dipole moment (µ) in Cs2Ag1−xNaxInCl6 as a function of Na content in the system. b) Parity change of the electron wavefunction of the STE before and after Na incorporation (pure and alloy). The cyan and magenta isosurfaces indicate electrons and holes c) Configurations showing strengthened STE confinement by the surrounding NaCl6 octahedra. d) STEs in Na-rich Cs2Ag1−xNaxInCl6. The STE is located in two neighboring octahedra. e) Configuration coordinate diagram of the STE formation in Cs2NaInCl6 (inset). Credit: Nature, doi: https://doi.org/10.1038/s41586-018-0691-0. This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.last_img read more