Bright inverted quantum-dot light-emitting diodes by all-solution processing

Abstract

Bright inverted quantum-dot light-emitting diodes (QLEDs) have been achieved by all-solution processing with Triton X-100-assisted PEDOT:PSS deposition.

54‐3: Bright Quantum Dots LEDs Enabled by Imprinted Random Nanostructures

“…Poly-TPD and PEDOT:PSS are widely used as HTL and HIL material due to their high hole-mobility, good energy level and solution-processability. Particularly, PEDOT:PSS solution is doped with Triton X-100 by a small ratio of 0.21 wt% to increase the wettability and adhesion at the interface of aqueous PEDOT:PSS/poly-TPD layer, enabling the solution-deposition of PEDOT:PSS onto the hydrophobic poly-TPD [8].…”

“…Considering the promise of QLEDs to be low-cost, wearable, disposable light emitting bandage products, photomedicine can be the niche in which QLEDs can perfectly fit without worrying about the lifetime issue. Recently, our group have demonstrated preliminary results of ultra-bright QLEDs-based photomedicine [7] and successfully developed all-solution processed inverted QLEDs to lower the cost [8]. Nevertheless, higher luminance, all-solution processed QLEDs are still preferred for more economical and efficient photomedical treatments.…”

“…On the other hand, the structure of our QLED devices consist of layers including indium tin oxide cathode (ITO) / ZnO nanoparticles & Cs2CO3 mixture layer (~10nm) / CdSe-ZnS-CdZnS core-shell-shell QDs (~23 nm) / poly (N,N9-bis(4butylphenyl)-N,N9-bis(phenyl)-benzidine) (poly-TPD,)/ poly(ethylenedioxythiophene):polystyrene sulphonate (PEDOT:PSS) /Al anode (100 nm). These inverted red QLED devices were fabricated by an all-solution process as described in previous report [8] and the prepared random grating structures were introduced onto poly-TPD layer by soft nanoimprint lithography as depicted in Figure1b. Fig.…”

“…In the SIH-QLEDs fabrication, a PFPE stamp was cast from the SIH sample and imprinted onto the poly-TPD layer. The rest steps followed the all-solution processing in previous report 8 .…”

37.3: Invited Paper: Update on Photoluminescent Perovskites and Electroluminescent Quantum Dots

“…Recently, an inverted red quantum dot light-emitting diode (QLED) with high peak brightness was achieved by all solution-processing, thanks to the enhanced coverage of uniform hydrophilic poly(ethylenedioxythiophene) / polystyrenesulfonate (PEDOT:PSS) hole injection layer (HIL) film on hydrophobic hole transport layer (HTL), which was enabled by doping PEDOT:PSS with non-ionic surfactant Triton X-100 [7]. With further light extraction enhancement through imprinting speckle image holography structures inside the devices, such all solution processed red QLEDs can reach up to a luminance of 146,000 Cd/cm 2 at 8V, 1.76 times to that of control devices with planar architecture, setting a new brightness record for allsolution processed inverted red QLEDs.…”