Perovskite LED realizes large area and high efficiency preparation

The reporter learned from the University of Science and Technology of China that Professor Xiao Zhengguo’s research group from the School of Physics of the school has made important progress in the field of large-scale preparation of perovskite LEDs. The research team used an air knife-assisted squeegee method to prepare a large-area, high-efficiency perovskite LED, which is an important step towards the commercial application of perovskite LED lighting. Related results were published in the journal Nature Communications.

Perovskite LED realizes large area and high efficiency preparation

Metal halide perovskite LEDs have become a new generation of LED devices because of their advantages such as wide color gamut, easy adjustment of bandgap, narrow luminous half-peak width, and ease of preparation. In 2014, it was reported for the first time that perovskite LEDs emitting light at room temperature have an external quantum efficiency (EQE) of less than 1%. In just a few years, the EQE of perovskite LEDs has exceeded 20%, which is close to commercial organic LEDs (The level of OLED) has shown broad application prospects in the field of lighting and display. However, the current high-efficiency perovskite LEDs are all prepared based on the spin coating method, and the device area is very small, only on the order of square millimeters, which cannot meet the needs of large-area commercial lighting. The blade coating method is a method based on the solution method to prepare large-area thin films, but the crystallization process of the perovskite film prepared by the blade coating method is not easy to control. The EQE of the prepared perovskite LED is only 1.1%. The device area is only 9 square millimeters.

In response to the above problems, Xiao Zhengguo’s research group took organic-inorganic hybrid perovskite CH3NH3PbI3 as the research object. By reducing the concentration of the perovskite precursor, 4-fluorobenzylamine was introduced and combined with air knife-assisted methods to make the film crystallization process more nucleation sites are formed in the medium, thereby preparing a uniform and dense perovskite polycrystalline film with a surface roughness of only 0.8 nanometers. The large-area perovskite film prepared by the knife coating method exhibits excellent uniformity in terms of thickness, surface roughness, fluorescence yield, and fluorescence lifetime. The EQE of the perovskite LED device prepared by the knife coating method is up to 16.1% (0.04 cm2) and 12.7% (1 cm2). The perovskite LED with a large area of 28 square centimeters emits a very uniform red light when working. At the same time, the research group also prepared flexible perovskite LEDs based on PEN/ITO substrates by squeegee coating, laying a foundation for the preparation of large-area flexible optoelectronic devices.

This research result fully demonstrates the feasibility of preparing large-area, high-efficiency perovskite LEDs by the squeegee method and the great prospect of applying it to commercial LED lighting.

Policies are issued to help the development of LED lighting industry

In recent years, in order to promote the rapid development of the LED lighting industry, China has successively introduced a series of industrial plans and policies related to LED lighting. Among them, the “Thirteenth Five-Year” urban green lighting plan was issued in August 2016 and 2017 July’s “Thirteenth Five-Year” development plan for the semiconductor lighting industry, January 2018 China’s optoelectronic device industry technology development roadmap (2018-2022), December 2018 “China’s phasing out incandescent lamps and accelerating the promotion of energy-saving lamps action plan 》, April 2019 on agreeing to launch the “ten cities and ten thousand” semiconductor lighting application project pilot work, July 2019 “Highway tunnel LED lighting design and construction technology guide”, December 2019 “Architectural lighting design standards (Draft for Solicitation of Comments). Then, due to the serious overseas epidemic, the General Office of the State Council issued the “Implementation Opinions on Supporting the Conversion of Exported Products to Domestic Sales” in June 2020, which clearly pointed out: encouraging enterprises to expand international markets while supporting exports The products are sold domestically to help foreign trade companies bailout.

Policies are issued to help the development of LED lighting industry

According to relevant data, the global LED lighting output value reached 601 billion yuan in 2018, and the global LED lighting output value reached 662 billion yuan in 2019. It is estimated that the global LED lighting output value will reach 728 billion yuan in 2020. From 2016 to 2018, my country’s LED lighting products have continued to grow. The output in 2018 was about 13.5 billion pieces. It is estimated that the output in 2019 will increase to 17.6 billion pieces, and the sales volume is estimated to reach 8.1 billion pieces. From the data, it can be seen that in my country The production and sales rate of LED lighting products is relatively stable. Under the background of the policy incentives of countries around the world and the growing demand for replacement of new and old light sources, the potential demand for the LED market has grown substantially. In the future, with the improvement of e-commerce channels and the advancement of Internet +, the penetration rate of the lighting industry will also increase dramatically.

Signify launches a new brand of LED lighting to meet the diverse needs of customers

In recent years, with the development of lighting technology, Chinese lighting users have a more in-depth interpretation of the functional characteristics of lighting products, and thus have higher requirements for lighting application experience. Facing such a terminal situation in the industry, how to make lighting products more competitive in user experience has become an important indicator of whether lighting channel distributors and electrical service providers can win the market.

Signify launches a new brand of LED lighting to meet the diverse needs of customers

Recently, Signify’s sub-brand Plylot officially entered the Chinese lighting market, and brought three important products: LED full-luminous ultra-thin flat light, LED flood light, and dual-end power LED tube, which is wholesale for China’s lighting Channel merchants and end-users bring new lighting application optimization solutions.

As one of the preferred brands of professional electricians in the world, based on the excellent reputation accumulated in the industry over the years, the high-efficiency, energy-saving, and reliable products of Plylot have been recognized and favored by distributors, electricians, and users of lighting wholesale channels in many parts of the world. . The three important products entering the Chinese market this time will bring business opportunities to Chinese lighting channel distributors and electrical service providers, as well as new application experiences for Chinese lighting users.

Higher light efficiency brings a more comfortable lighting experience

In the after-sales service of China’s lighting wholesale channel distributors, customers often complain about the uncomfortable visual effects of the LED lamps they purchase. When dealing with this type of problem, dealers often need to contact the technical staff of the lighting manufacturer to find a suitable time to help customers check the light-emitting problem of the lighting. They also need to contact the electrical service provider to solve a series of processes such as lighting disassembly and assembly. This requires a lot of manpower, material resources, and various expenses, and the final problem may not be finally solved. The most unfavorable thing for dealers is that the emergence of lighting efficiency problems will affect their recognition in the eyes of customers, and will have a negative impact on future market operations.

The problem with the luminous efficiency of LED lamps is that manufacturers only pay attention to the luminous brightness of the light source and have not formulated an effective light distribution plan. In view of the light comfort problem of Chinese lighting users for LED lighting products, the three major products of Puri Le have made unique optical design: its LED all-luminous ultra-thin flat light adopts a full-size light-emitting high-efficiency optical design, which is visually uniform. Spots, even when shooting with mobile phones, there will be no stroboscopic; its LED floodlight has a textured tempered glass mask, which not only increases the aesthetics of the lamp body but also makes the light soft and comfortable, reducing the irritation of glare to the eyes, through ultra-thin integration The style design greatly reduces the exposure of the lamps and achieves the effect of “seeing the light but not the light”. It is a perfect substitute for traditional floodlights; its double-ended power-in LED tube uses high-quality chips to achieve light efficiency. Up to 100lm/W, achieving 1600lm light output, the brightness is equivalent to 36W fluorescent tube, not only high efficiency and energy saving but also in line with IEC62471 non-light biological hazard standards, ensuring eye health.

The unique optical design of the three major products of Puli Le allows distributors participating in product marketing to sell products while also promoting a lighting light perception service to end lighting users, allowing those participating in the brand’s product wholesale channel promotion Merchants have changed from user-selectable “light sellers” to “light sellers” users vying to choose, enhancing their market credibility.

Standards for LED lighting products to enter the Vietnamese market

From January 1, 2020, Vietnam has begun to enforce the energy efficiency labeling program for LED lighting products.

Standards for LED lighting products to enter the Vietnamese market

According to Resolution No. 04/2017/QD-TTg Decision of the Ministry of Industry and Trade (MOIT) of Vietnam, LED lights are included in the control of Vietnam’s energy efficiency regulations. Energy efficiency labels can only be applied after meeting the minimum energy efficiency standards and obtaining the energy efficiency declaration DoC. Sold to the Vietnamese market, the mandatory implementation date is January 1, 2020.

Applicable regulations:

1. Decision No.04/2017/QD-TTg: Comply with the provisions of the equipment list of Vietnam energy efficiency regulations;

2.Circular 36/2016/TT-BCT: According to the requirements of the conformity declaration procedure and required documents of the Vietnam National Energy Efficiency Plan (VNEEP);

3. Decision No. 4889/QD-BCT: The official announcement and guideline for applying MEPS standard for LED lighting.

standard test:

1. TCVN 11843: 2017-Test methods for LED bulbs, LED lamps and LED modules;

2. TCVN 11844: 2017 – Energy efficiency of LED lighting products.

Note: In the initial stage of mandatory, MEPS and EE DoC are only mandatory for LED lamps with E27 and B22 self-ballasted LED bulbs and G5 and G13 double-headed LED tubes with a maximum power of 60W and a nominal voltage not exceeding 250V. The MEPS implementation roadmap for other products (LED illuminators, LED modules, etc.) will be released by MOIT in the future. You can also apply for voluntary energy efficiency label certification.

DoC procedure application documents:

1. Vietnam Energy Efficiency Declaration of Conformity (DoC);

2. Energy efficiency test report;

3. Energy label design.

Note: The certificate holder is only allowed to use the Vietnamese energy efficiency label after completing the DoC procedure.

Energy efficiency label style of lighting products:

From June 1, 2020, Vietnam will start the safety and EMC control of LED lighting products, and enforce CR Mark.

In September 2019, the Ministry of Science and Technology (MOST) of Vietnam issued Circular No.08/2019/TT-BKHCN, which approved the technical regulations QCVN19: 2019/BKHCN for the safety and EMC requirements of LED lighting products, and implemented CR Mark certification.

Implementation schedule:

From June 1, 2020, domestic and imported LED lights must meet safety and electromagnetic interference (EMI) requirements (QCVN19: 2019/BKHCN Section 2.1.2; 2.1.3 and 2.2.1);

From June 1, 2021, domestic and imported LED lights must meet all the requirements of QCVN19: 2019/BKHCN: including safety, EMI and EMS;

Individuals and companies are encouraged to apply for the certification of LED lights voluntarily according to QCVN19: 2019 / BKHCN from December 31, 2019.

Replacement of electric lights in the basement of the building with induction LED lights

The New Taipei City Public Works Bureau has put forward the “Replacement Subsidy Plan for the Lighting Replacement of Indoor Parking Lots in Multi-unit Residential Buildings” in 107. If the basement lamps in the community are old, they should be replaced with energy-saving lamps according to regulations. The luminous efficiency of LED bulbs must meet the standard and must have automatic switching, dimming or timing control, etc., communities with more than 500 households can receive a subsidy of up to 800,000 RMB.

Replacement of electric lights in the basement of the building with induction LED lights

If the lamp equipment in the basement garage of the community is old, the community can apply for subsidies from the New Taipei City Works Bureau when replacing the lamps. The Works Bureau emphasized that the replacement lamps must have energy-saving and point-saving labels, and must be “inductive” LED lamps with a luminous efficiency greater than 120 (lm/w); the subsidy amount can account for up to half of the total amount, and the number of community households is not Up to 200, the maximum limit is 200,000, between 200 and 500 households, the upper limit is 400,000, and the upper limit is 800,000 for communities with 500 households or more.

The Public Works Bureau stated that the community’s replacement of basement lamps must hold a “differentiated ownership meeting”, which can only be replaced after more than half of the households agree. If the meeting is held late or a consensus is not reached, it may delay the community’s application for subsidies. Therefore, the lighting replacement subsidy in 107 has been postponed to the end of September this year to facilitate the application for the replacement of lamps in 107 communities; if the community is happy with lamps in 108, you can still apply for the 108 projects subsidy based on the issuance time on the invoice.

The Bureau of Works said that about 60 communities have applied for the 107 subsidy program, and 6.9 million have been subsidized. The total budget of the 108-year program is about 15 million, encouraging communities to replace lamps with energy-saving lamps; New Taipei City has received subsidies, Communities will also conduct spot checks because of the huge amount of subsidies in communities with more than 500 households. The proportion of spot checks is 100%. In communities with less than 200 households, the sampling rate is over 10%.

LED combined with AI to create the best in-store lighting system

German Research Center for Artificial Intelligence; DFKI and the European Agency for Technology and Innovation (EIT) team up with a supermarket in Saarbrücken, Globus, Philips Lighting, and other companies to conduct pilot experiments to study how the differences in color lighting systems combination affect sales and customer behavior.

LED combined with AI to create the best in-store lighting system

In this experiment, the researchers spent two months testing different lighting conditions in the promotion display area of about 180 square meters in the supermarket (equipped with Philips StoreWise and LED lighting system). The researchers tested three settings: uniform overhead chandeliers in the store, general spotlights, and a combination of spotlights and soft-colored uplights.

The 58 spotlights used in the experiment enhanced the contrast and increased the color uplights (for the ceiling), thereby enhancing the appearance of the product, and also helping to distinguish the promotion area so that the product can be seen from a farther place to creates a unique atmosphere and changes the mood of shoppers.

Each light point in the lighting system can be independently controlled through the Philips StoreWise web application and can be individually adjusted according to color, brightness, and saturation. Sensors in the ceiling and 300 shopping carts are used to record the number of visitors and the time they spend in the area compared to the rest of the store. In addition, the researchers analyze the data to compare the sales figures and check the number of products purchased from this special lighting area.

According to this study, the most attractive setting for consumers is the use of spotlights with soft-colored uplights, which can help increase sales by 6% in the promotion zone. Compared with the standard lighting settings in the store, the same colored light set can create the best customer pause time for the promotion area, increasing the customer visit rate by about 15%. And just replacing traditional lighting fixtures with spotlights increased the customer visit rate by 7%.

“Using next-generation lighting systems like Philips StoreWise and indoor positioning systems, it is expected that retail stores can analyze in-store sales and traffic data in real-time, and adjust lighting conditions to optimize sales,” Gonneke, senior marketing director, Philips Lighting Gros said.

The result of this experiment in the Globus supermarket is to force stores to install StoreWise and LED lighting systems as soon as possible.

New LED challenges laser lamps

LED lamps are already the mainstream equipment of automobiles, with two major advantages of energy-saving and durability, making traditional halogen lamps or HID lamps have gradually disappeared; due to the small size of LEDs, there are better flexible applications in the design of headlights. A major breakthrough in LED technology, with stronger lighting distance and energy-saving effects, can even challenge more advanced laser headlights.

New LED challenges laser lamps

Shuji Nakamura was the winner of the 2014 Nobel Prize in Physics, also known as the father of blue LEDs. Based on the research results of blue LEDs, he produced a pure white LED lamp. Under the supervision of Nakamura Shuji, SLD Laser launched a new LED. White light, this new LED luminaire has a lighting distance of up to 1 km and consumes less energy than traditional LEDs, pushing the capabilities of LED luminaires forward.

The performance of SLD Laser’s LED lamps is comparable to that of laser headlamps. At present, both BMW and Audi have laser headlamp technology. Laser lamps use laser beams to project to the reflector to produce a strong beam, which consumes less energy than ordinary LEDs, but costs Expensive and only equipped in high-end cars; LED lights developed by SLD Laser are already comparable to laser lights in performance. In addition, they are low in cost, easy to replace and small in size. In order to verify the performance of the lights, SLD Laser won the Baja 1000 off-road rally champion Cameron Steele’s car is equipped with a new type of LED light. This group of lamps is used for night searches. Due to the powerful performance of this LED lamp, due to the differences in lighting regulations in various countries, the new LED will be the first to be used in competitions or special purposes. It may replace laser headlights in commercial vehicles and stabilize the dominant position of LED lamps.

Samsung develops blue QLED technology

Since abandoning the large-screen OLED technology route, Samsung has been increasing the research and development of QLED quantum dot technology, and most of its TV products also use QLED technology. At present, the advantage of QLED is that it can greatly increase the color gamut coverage of TVs and display more colors. However, the current QLED is far away from the “complete body” of electroluminescence.

Samsung develops blue QLED technology

The current QLED TVs on the market are still LCD TVs in essence, and the backlight is still an LED light source, but a layer of quantum dot film is added between the backlight and the liquid crystal to improve the color performance of the picture. The future of QLED is electroluminescent quantum dots. Like OLED, the pixels emit light, and there is no life-span problem of OLED organic light-emitting materials, and it will not burn the screen.

Although it is still far from the realization of electroluminescence technology, Samsung has never given up on exploration. Recently, Korean media reported that Samsung successfully developed blue QLED technology, which can increase the luminous efficiency of the screen by 20%, achieve a maximum brightness of 88,900 nits, and extend the QLED handle to 16,000 hours.

The so-called quantum dots are semiconductor particles with a diameter of nanometers. When illuminated, photoluminescent quantum dots emit light of different colors according to their size. Blue is the most difficult color among the three primary colors of QLED and has the largest band. The gap will be oxidized when exposed, which will shorten the service life and reduce the luminous efficiency.

Samsung said that the researchers used a double emission layer and a short ligand structure on the surface of the blue quantum dot, and increased the current injection rate to ensure the long-lasting light response of the quantum dot material. This technological innovation is expected to accelerate the implementation of electroluminescent quantum dot technology as soon as possible.

Fully LED street light in Gaoshi

Say goodbye to traditional lighting fixtures. The 240,000 street lights in Gaocheng will be fully LED, which is expected to be completed before the end of the year. The Gao City Public Works Bureau will also modify the “smart street light” system for 80,000 street lights in the urban area. Once the lights are damaged, they can be reported back through the Internet immediately, saving the maintenance department’s labor and cost for patrolling street lights at night.

Fully LED street light in Gaoshi

Since 2013, Gaoshi has gradually replaced high-pressure sodium gas lamps or metal-clad lamps. As of 2019, 120,000 LED street lamps have been replaced. Many of the lamps that have been out of warranty but have not been damaged have long been decayed. Fully updated together. At present, the overall refurbishment progress in the 35 districts of the city has reached 80%. Qianjin, Yancheng, Mi Tuo and Liugui districts have all been refurbished, and Renwu, Taishe, Tianliao, and Meinong districts have reached 90%. All replacements are expected to be installed by the end of the year.

The Bureau of Public Works stated that the subsidy from the Energy Bureau of the Ministry of Economic Affairs was limited before 2019, and only 120,000 LED street lights could be replaced in 7 years. Introducing private financing this year, and signing the “Energy-saving and Smart Street Lamp PFI (Private Finance Initiative, Private Finance Initiative)” replacement plan with two LED manufacturers. The manufacturer installs brand-new LED lamps and replaces the LEDs to save electricity costs. The manufacturer submits an application every six months. The Bureau of Works estimates that it takes about 8 years for manufacturers to pay back their costs.

The new LED street lamp consumes 70 watts of electricity per lamp, and the main roads such as Zhongshan Road use high-brightness 100 watt lamps. The Bureau of Public Works estimates that it can save about 108 million RMB in electricity bills, reduce power consumption by about 70 million kWh, and reduce carbon emissions by about 37,000 tons per year.

In addition, this year the Works Bureau also started to deploy “smart street lights” for street lights in urban areas. A black box for sensing is installed on the LEDs. Once damaged or unlit, it will be sent back to the system through the wifi generator to improve Rush repair efficiency.

The Bureau of Public Works emphasized that the illuminance and brightness of the new LED street lights meet the requirements. In response to some people’s dazzling response, engineers will adjust the angle of the street lights or install shading facilities to improve it.

2020 The global LED component market declines by 15%

Industrial Technology International Strategic Development Institute of Industrial Technology Research Institute recently released its latest estimate that the global LED component market may decline by 15% in 2020. Before March this year, the novel coronavirus pneumonia epidemic was mainly locked in mainland China. At that time, the hidden worries on the manufacturing side had gradually eased. However, after March, the epidemic in Europe and the United States caused the stagnation or decline of the LED demand-side market, which became the biggest cause of the LED component market decline. The epidemic can be effectively controlled in May, and the demand for LED components has a chance to return to the right track; once the epidemic drags into the second half of the year, the market estimate may have to be revised down again, because of unemployment pressure and consumption tightening, the recovery period may last more than 10 months.

2020 The global LED component market declines by 15%

Researcher Huang Mengjiao of the Institute of Industrial Technology International Strategy Development of the Industrial Technology Research Institute pointed out that the global LED components are expected to decline by more than 15% this year. Such a big recession has never been seen in the past, and the Eurozone market has suffered the most. If the new crown pneumonia epidemic is locked in the mainland, it is only a problem on the supply side, but the impact has all expanded to the market, and terminal LED demand has stagnated.

The main application markets for LED components are LCD TVs and portable products such as backlights, lighting, billboards, and automotive. The automotive market has fallen sharply in 2019, impacting the revenue of major LED component manufacturers; and most of the LED lighting is The commercial market is regularly updated and overhauled. Now, most areas of the world are restricting activities, and many commercial places are not even open for business. The lighting market has no prospects.

According to the latest forecast by Gartner, international research and consulting agency, in April this year, affected by the new crown pneumonia, LED backlight application markets such as NB, tablet computers, mobile phones, and LCD TVs have experienced a decline of about 5% to 15%. NB declined by more than 10%, and LCD TV declined by 15% the most. Huang Mengjiao pointed out that LCD TV was originally a saturated market, with shipments of 226 million units in 2019, which is expected to decline by 15% this year. The impact of the LED backlight application market is inevitable.