[ad_1]
We talked about perovskite and its ability to interact with light in this article, subsequently deepening the discussion regarding its use in photovoltaic panels, in tandem with silicon.
Recently this material has also been adopted to improve LED technologysurpassing his own more critical limits thanks to a new intuition. Indeed, perovskite LEDs have always been quite promising because they can be easily and cost-effectively produced, are very light and more flexible than OLEDs (organic light-emitting diodes, the next step up from liquid crystals), and have the same color purity and tunability as LEDs based on III-V semiconductors.
However they turned out unstable and not very durable due to the ionic nature of their crystalline structures, responsible for the rapid degradation of the material; furthermore the typical duration of the Perovskite LEDs were on the order of 10-100 hours versus the minimum lifetime required for an OLED display of 10,000 hours.
Some researchers of the PEROLED Korean, Seoul National University and the Korea Basic Science Institute (KBSI), together with scientists from the University of Cambridge in the United Kingdom, have investigated a way to overcome these limitations creating an ultra-bright, efficient and stable perovskite LED made of core/shell perovskite nanocrystals with a dimension of about 10 nm, obtained by means of a simple reaction, which took place in situ, between the additive of benzylphosphonic acid (BPA) with three-dimensional films of polycrystalline perovskitewithout separate synthesis processes.
During the reaction, the large 3D crystals were split into nanocrystals surrounded by the BPA, achieving strong vector confinement. The BPA free shell proved capable of passivating undercoordinated lead atomsor to slow down or completely prevent its corrosion, forming covalent bonds and maintaining good charge transport properties for 3D perovskites.
The team created efficient, bright and stable perovskite LEDs with a maximum brightness of approximately 470,000 cd m−2, maximum external quantum efficiency of 28.9% (average = 25.2 ± 1.6% across 40 devices), maximum efficiency current of 151 cd A−1 and half-life of 520 hours at 1,000 cd m-2 (estimated half-life > 30,000 hours at 100 cd m-2).
Their work will make great strides in the potential of perovskite-based LEDs to be commercialised, in the future, in the display sector and beyond. The full study was published in the journal natures.
.
[ad_2]
Source link
