Cathode made by silver-precursor ink for all-solution processed quantum dots light-emitting diodes

To realize all-solution processed quantum dots (QDs) light-emitting didoes (QLEDs) with every functional layer processed via wet coating, silver-precursor ink converted cathode is introduced for the first time. One challenge to utilize solution-processed cathode is that the silver-precursor ink reacts with the electron transport layer zinc oxide (ZnO). Another one is that the silver ions permeate through ZnO to quench the QDs' fluorescence. To overcome the challenges, the annealing temperature of ZnO is optimized to 180 degrees C, while the silver-precursor ink's annealing condition of 180 degrees C/5 min is selected. As a result, the all-solution processed QLEDs achieve a maximum brightness of 1.32 x 10(4) cd m(-2) , a maximum current efficiency of 8.98 cd A(-1) , and a maximum external quantum efficiency of 6.92% which reaches 61% of the efficiency of QLEDs with evaporated silver cathode.

Automated summary

In this study, a silver-precursor ink converted cathode is introduced for all-solution processed quantum dots light-emitting diodes (QLEDs). By optimizing the annealing temperature of ZnO and the annealing condition of the silver-precursor ink, the challenges of silver ions permeating through ZnO and quenching the fluorescence of QDs have been overcome, leading to high efficiency QLEDs.