LED - Page 3

Perovskite nanocrystals (PNCs) have considerable potential as next-generation display materials thanks to their excellent photoluminescence quantum yield (PLQY), wide color gamut, and narrow emission bandwidth. However, due to their weak stability against solvents, their patterning remains a challenge. In a recent study, researchers at Ajou University, Hanyang University, Sungkyunkwan University, Macquarie University and Kongju National University developed functional organic ligands (AzL1-Th and AzL2-Th) for the fine pixelation of perovskite nanocrystal (PNC) displays. 

Functional ligands containing photocurable azide moieties exhibit good charge transport properties and fast and efficient photocrosslinking performance, while maintaining a high PLQY. The team successfully demonstrated the crosslinked PNC light emitting diodes using AzL1-Th. The results suggest the high potential of photocurable ligands for the micro-patterning of PNC films without film damages.

Researchers at the University of Cambridge, University of Science and Technology of China, Shanghai Jiao Tong University, Soochow University, OIST, Hong Kong University of Science and Technology, Victoria University of Wellington and Kyushu University have demonstrated efficient blue perovskite LEDs based on a mixed two-dimensional–three-dimensional perovskite and a multifunctional ionic additive that enables control over the reduced-dimensional phases, non-radiative recombination channels and spectral stability. 

The team reported a series of devices that emit efficient electroluminescence from mixed bromide/chloride quasi-three-dimensional regions, with external quantum efficiencies of up to 21.4% (at a luminance of 22 cd m^–2 and emission peak at 483 nm), 13.2% (at a luminance of 2.0 cd m^–2 and emission peak at 474 nm) and 7.3% (at a luminance of 6 cd m^–2 and emission peak at 464 nm). The devices showed a nearly 30-fold increase in operational stability compared with control LEDs, with a half-lifetime of 129 min at an initial luminance of 100 cd m^–2. 

Perovskite-Info is proud to announce an update to our Perovskite for the Display Industry Market Report. This market report, brought to you by the world's leading perovskite and OLED industry experts, is a comprehensive guide to next-generation perovskite-based solutions for the display industry that enable efficient, low cost and high-quality display devices. The report is now updated to February 2024, with all the latest commercial and research activity. This was a major version, with over 15 updates, new companies and new technologies covered.

Reading this report, you'll learn all about:

• Perovskite materials and their properties
• Perovskite applications in the display industry
• Perovskite QDs for color conversion
• Prominent perovskite display related research activities

The report also provides a list of perovskite display companies, datasheets and brochures of pQD film solutions, an introduction to perovskite materials and processes, an introduction to emerging display technologies and more.

Researchers at the Chinese Academy of Sciences (CAS), University of Nottingham Ningbo China and University of Science and Technology of China have developed a novel solvent sieve method that significantly enhances the performance and operational stability of perovskite light-emitting diodes (PeLEDs).

Perovskites' practical application in PeLEDs has thus been constrained by their low operational stability. The recent research, centered on a comprehensive analysis of perovskite nanostructures, identified the presence of defective low n-phase perovskites as a primary factor undermining device stability. These defective phases, characterized by a minimal number of lead ion layers, arise from rapid and uncontrolled crystallization processes. The simple solvent sieve treatment reported in this study addresses this issue and improves the efficiency and stability potentials of high-brightness perovskite light-emitting diodes for future commercial applications.

Researchers at Seoul National University and Korea Advanced Institute of Science and Technology (KAIST) have developed highly efficient tandem perovskite light-emitting diodes (PeLEDs). This advancement may expedite the commercialization of perovskite light-emitting materials in next-generation display technologies.

The Ministry of Science and ICT (MSIT) announced that the team, led by Professor Lee Tae-woo from Seoul National University’s College of Engineering, has successfully created a high-efficiency and long-life hybrid tandem light-emitting device. This device combines metal halide perovskites with organic light-emitting diodes.

Researchers at Imec have reported a metal halide perovskite LED (PeLED) stack that emits 1,000x more light “than state-of-the-art OLEDs”. The team developed a transparent PeLED architecture, that combines low optical losses with excellent current-injection properties. 

In this work, the team showed that perovskite semiconductor optical amplifiers and injection lasers are within reach using this type of transparent PeLED.

Researchers at Yonsei University and Korea University have integrated perovskite films with two-dimensional electronics to address current obstacles that hinder the commercialization of perovskite LEDs (PeLEDs). 

The scientists developed centimeter-scale integrated PeLED displays achieving key metrics on par or better than existing standards. This work suggests the potential transition of PeLEDs from lab concept to next-generation commercial displays.

It was reported that researchers at the Institute for Advanced Materials at the Universitat Jaume I in Castelló have created a method for synthesizing organic-inorganic tin halide perovskites and generating thin films or coatings from them, which, when deposited on substrates, have optoelectronic properties that are useful for the creation of devices such as perovskite-based LEDs (PeLEDs).

The method developed by the team consisting of Dr. Samrat Das Adhikari and the doctoral student, Jesús A. Sánchez Diaz, and led by the researcher Iván Mora Seró, exhibits excellent photoluminescence and stability properties that are suitable for commercial application in the field of optoelectronic devices (solar cells, LEDs, etc.).

Researchers in Sweden and China have studied the reasons behind the short operational lifetime of blue perovskite-based LEDs (PeLEDs). 

While perovskite light-emitting diodes (PeLEDs) have seen unprecedented development in device efficiency over the past decade, they still suffer from poor operational stability. This is especially true for blue PeLEDs, whose operational lifetime remains orders of magnitude behind their green and red counterparts. The scientists in this work have systematically investigated this efficiency-stability discrepancy in a series of green- to blue-emitting PeLEDs based on mixed Br/Cl-perovskites. Typically, mixed chloride/bromide perovskites are employed to produce ideal blue emission. However, the researchers have uncovered a counterintuitive fact: even minute quantities of chloride loading can have a dramatic negative impact on the operational lifetime of these devices. 

Researchers from Lawrence Berkeley National Laboratory (Berkeley Lab) and UC Berkeley have developed room-temperature-solution (20 °C) and low-temperature-solution (80 °C) synthesis procedures for a new class of metal halide perovskite high-entropy semiconductor (HES) single crystals. The “multielement ink” could enable cost-effective and energy-efficient semiconductor manufacturing and accelerate the sustainable production of next-gen microelectronics, photovoltaics, solid state lighting, and display devices.

“The traditional way of making semiconductor devices is energy-intensive and one of the major sources of carbon emissions,” said Peidong Yang, the senior author on the study, a faculty senior scientist in Berkeley Lab’s Materials Sciences Division and professor of chemistry and materials science and engineering at UC Berkeley. “Our new method of making semiconductors could pave the way for a more sustainable semiconductor industry.”