LEDs dominate the lighting industry today, but a number of emerging technologies promise further improvement.
For example, there is organic LED, which uses organic molecules to emit light, enabling thin, flexible and vibrant displays.
There is quantum dot LED, which uses tiny semiconductor particles called quantum dots for improved colour and brightness.
And then there is ‘micro LED’, which uses tiny LEDs to get higher brightness and colour.
All of these, however, suffer from a drawback. They are expensive; moreover, QLEDs use toxic materials.
But there is one technology that combines the best of OLED and QLED, while remaining cost-effective — perovskite LED (PeLED).
However, perovskites are inherently unstable.
Now, researchers at the Centre for Nano and Soft Matter Sciences (CeNS), Bengaluru, have developed a method to improve the stability of PeLEDs by minimising anion migration — a key cause for colour instability, heat, and moisture sensitivity.
The team, led by Dr Pralay K Santra, has developed a method that uses cesium lead bromide nanocrystals to tackle the problem of instability.
Santra’s team used an ‘argon-oxygen plasma treatment’, a process that creates a protective barrier and prevents anion migration.
This breakthrough brings PeLEDs closer to real-world applications, paving the way for more efficient and durable optoelectronic devices, says a press release from the governmental Department of Science and Technology.
Fatigue-resistant alloy
Researchers have developed an innovative approach to designing fatigue-resistant multi-principal element alloys (MPEAs), opening new possibilities for their application and further exploration.
MPEAs are a novel class of materials, composed of multiple principal elements.
Traditionally, it is believed that increasing strength through compositional modifications or the addition of brittle phases adversely affects fatigue life.
Challenging these notions, Dr Ankur Chauhan and his team from the Department of Materials Engineering, Indian Institute of Science (IISc), Bengaluru, systematically explored the role of two critical microstructural features in enhancing the low-cycle fatigue (LCF) performance of alloys in the ‘chromium, manganese, iron, cobalt, nickel’ system.
“By adjusting the Cr/Ni (chromium-nickel) ratio, they synthesised two single-phase face-centred cubic (FCC) MPEAs with distinct SFEs (stacking fault energy). The low-SFE alloy exhibited 10–20 per cent higher cyclic strength than the high-SFE alloy while maintaining a comparable fatigue life,” says a press release.
Additionally, the team developed a dual-phase alloy that demonstrated 50–65 per cent increase in cyclic strength over the single-phase low-SFE alloy, while maintaining a similar fatigue life.
These findings provide a framework for designing both single-phase and dual-phase fatigue-resistant MPEAs, with implications for structural applications. By offering insights into deformation and damage mechanisms, this work advances the understanding of how SFE and secondary brittle phases influence the mechanical properties of MPEAs.
