August 2020

NUS researchers have developed transparent, near-infrared perovskite light-emitting diodes (LEDs) that could be integrated into the displays of smart watches, smart phones and augmented or virtual reality devices.

a A transparent PeLED overlaid across a smart-watch display to show high optical transparency and neutral color. b Near-infrared photo showing bright NIR electroluminescence from the transparent PeLED above the smart-watch display. Image from article

These transparent devices are constructed with an ITO/AZO/PEIE/FAPbI₃/poly-TPD/MoO₃/Al/ITO/Ag/ITO architecture, and offer a high average transmittance of more than 55% across the visible spectral region.

Researchers from East China University of Science and Technology and Australia-based Griffith University have examined the effects of surface decoration of perovskites on the stability of resulting perovskite solar cells. They reported that such configurations have shown to be more stable than the untreated surface of perovskites.

The team reported a chelation strategy for surface engineering of CsPbI₂Br perovskite, in which dithiocarbamate molecules can be coordinate to surface Pb sites via strong bidentate chelating bonding. Such chelated CsPbI₂Br perovskite can realize excellent passivation of surface under-coordinated defects, reaching a power conversion efficiency of 17.03% and an open-circuit voltage of 1.37'V of CsPbI₂Br solar cells.

Research using the Canadian Light Source (CLS) at the University of Saskatchewan could help bring perovskite QDs display technology closer to commercilization.

Quantum dots are nanocrystals that glow, a property that scientists have been working with to develop next-generation LEDs. When a quantum dot glows, it creates very pure light in a precise wavelength of red, blue or green. Conventional LEDs, found in TV screens today, produce white light that is filtered to achieve desired colors, a process that leads to less bright and muddier colors.

Researchers from Pohang University of Science and Technology in Korea have received Universal Display Corporation's 2020 Innovative Research and Pioneering Technology Award in Organic Electronics & Display, for their work 'High-Performance and Reliable Lead-Free Layered-Perovskite Transistors'. Universal Display (UDC) is a large OLED research company, considered to be a pioneer in field.

In their work, the scientists explain that despite extensive examination of perovskites' potential use in solar cells and light'emitting diodes, research on their applications in thin'film transistors (TFTs) has drawn less attention despite their high intrinsic charge carrier mobility. In this study, the universal approaches for high'performance and reliable p'channel lead'free phenethylammonium tin iodide TFTs are reported.

The Institute for Solar Energy Research Hamelin (ISFH), the Karlsruhe Institute of Technology (KIT) and the Institute for Materials and Components in Electronics at the University of Hannover, as well as Centrotherm, Singulus, Meyer Burger and Von Ardenne, are involved in a research project aimed at achieving 33%-efficient perovskite-silicon tandem solar cell suitable for mass production.

The new research project is called '27plus6′ and it brings together the expertise of leading German and Swiss technology companies and research institutes. The consortium said that it aims to achieve the promised conversion efficiency under standard test conditions, and that is also seeking to reach a higher power yield, intended to accelerate industrial implementation.

Scientists from the Korea Institute of Machinery and Materials, Kyungpook National University, Sungkyunkwan University, Sejong University and Yonsei University in Korea, in collaboration with Uppsala University in Sweden, Imperial College London and National Renewable Energy Laboratory in the U.S, recently devised a way to sustainably collect pollutants secreted from PSCs without sacrificing the panel itself. Using this new approach, the scientists were able to safely recycle 99.7% of lead in their samples.

In the study describing their work, the researchers explain that they're not the first to attempt to tackle this issue, but that previous approaches to adsorbing lead have been limited by the number of naturally occurring lead solvents.

Singapore-based Nanolumi unveiled several display prototypes that adopt the company's perovskite quantum dots films.

In the video above, you can see a 32" mini-LED display, a 24" edge-lit LCD monitor and a 10-inch tablet. The company says its cadmium-free films combine the industry's narrowest color spectrum.

A team of researchers, led by Professor Yang Yang from State Key Laboratory of Modern Optical Instrumentation, College of Optical Science and Engineering, International Research Center for Advanced Photonics, Zhejiang University, China, and co-workers have developed a nontoxic double perovskite scintillator, which exhibits not only a high light yield but also long-term stability under continuous thermal treatment and X-ray irradiation. Scintillators are a key component for detection of X-rays, which convert X-ray photons to visible photons so they are then detected by a photodiode array.

Given the high light output and fast light decay of this new scintillator, static X-ray imaging was attained under an extremely low dose of ~1 μGyair, and dynamic X-ray imaging of finger bending without a ghosting effect was demonstrated under a low dose rate of 47.2 μGyair s-1. These results reveal the huge potential in exploring scintillators beyond lead halide perovskites, not only for avoiding toxic elements but also for achieving higher performance.

A recent research by Barry Rand, associate director for external partnerships and associate professor of electrical engineering and the Andlinger Center for Energy and the Environment, with a team of researchers, has advanced perovskite-based LEDs by significantly improving the stability and performance by better managing the heat generated by the LEDs.

The research identifies several techniques that reduce the accumulation of heat within the material, which extended its lifetime tenfold. When the researchers prevented the device from overheating, they were able to pump enough current into it to produce light hundreds of times more intense than a typical cell phone display. The intensity, measured in watts per square meter, reflects the real amount of light coming from a device, uninfluenced by human eyes or the color of the light. Previously, such a level of current would have caused the LED to fail.

The U.S. Department of Energy (DoE) recently announced $20 million in funding to advance perovskite photovoltaic technologies. To be competitive in the marketplace, perovskite's long-term durability must be tested and verified, which is the aim of this funding opportunity through DOE's Office of Energy Efficiency and Renewable Energy (EERE).

'Perovskites are a promising solar technology that could help us reach the next level of innovative and efficient solar power,' said Deputy Secretary of Energy Mark W. Menezes. 'Our goal is to further advance this technology here in the United States. The research and development supported by this $20 million investment will help us better understand how perovskite solar cells, which can be manufactured quickly, can further this mission.'