Hybrid Liquid Metal Cathode Enables High-Performance Intrinsically Stretchable OLEDs.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 41457698.
- Also identified by DOI 10.1002/adma.202518254 and PMC identifier 13137763.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
Intrinsically stretchable light-emitting diodes (LEDs) are essential for next-generation wearable and implantable optoelectronics. However, achieving high-performance in intrinsically stretchable LEDs remains elusive due to the absence of a stretchable cathode that concurrently ensures efficient electron injection, mechanical compliance, and high optical reflectance. Here, we introduce a hybrid liquid metal-liquid metal particle (Hyb-LM) cathode, engineered by selective rupture of surface liquid metal particles (LMPs), which facilitates their transformation into a continuous liquid metal (LM) layer. The resulting bilayer structure, comprising a surface LM layer and an underlying LMP layer, exhibits an exceptional combination of low work function (∼4.1 eV), high reflectance (∼90%), low sheet resistance (2.70 × 10<sup>-</sup> <sup>2</sup> Ω sq<sup>-1</sup>), and negligible resistance changes under 150% strain (R/R<sub>0</sub> = 1.03 at 150% strain), overcoming fundamental limitations in state-of-the-art stretchable cathodes. The Hyb-LM cathode enables the realization of intrinsically stretchable organic LEDs with a low turn-on voltage of 3.0 V, a maximum luminance of 17 670 cd m<sup>-2</sup>, and a record-high current efficiency of 10.35 cd A<sup>-1</sup>, representing a critical advancement toward stretchable displays and implantable optoelectronics.