Perovskite nanocrystals (PNCs) have considerable potential as next-generation display materials thanks to their excellent photoluminescence quantum yield (PLQY), wide color gamut, and narrow emission bandwidth. However, due to their weak stability against solvents, their patterning remains a challenge. In a recent study, researchers at Ajou University, Hanyang University, Sungkyunkwan University, Macquarie University and Kongju National University developed functional organic ligands (AzL1-Th and AzL2-Th) for the fine pixelation of perovskite nanocrystal (PNC) displays.
Functional ligands containing photocurable azide moieties exhibit good charge transport properties and fast and efficient photocrosslinking performance, while maintaining a high PLQY. The team successfully demonstrated the crosslinked PNC light emitting diodes using AzL1-Th. The results suggest the high potential of photocurable ligands for the micro-patterning of PNC films without film damages.
These “all-in-one” organic ligands display various functionalities of efficient dispersion, photocuration, and charge transport capability by employing electron-rich thiophene ring in the ligands (AzL1-Th and AzL2-Th).
AzL1-Th and AzL2-Th were spontaneously attached to the surface of CsPbBr3 PNCs through one-pot synthesis. In addition, AzL1-Th exhibited high charge carrier mobility and enabled PNCs to produce high PLQY (88 %). The CsPbBr3 PNCs attached to AzL1-Th (AzL1-Th-PNCs) were readily crosslinked after UV light irradiation via a photocuring reaction between the azide units in the ligands.
Using this approach, patterning of AzL1-Th-PNC films and crosslinked PNC LEDs was successfully demonstrated.