Efficient and stable inverted RGB quantum-dot-electrolyte LEDs for active-matrix displays

Quantum dots (QDs) are promising for optoelectronic applications, and the exploration of QD-electrolyte (QE) may endow distinctive optical and electronic characteristics. However, the performance of red QE-based light-emitting diodes (QE-LEDs) is limited, and green/blue QE-LEDs have not been reported. Here, we report an inverted architecture that eliminates solvent compatibility issues, enabling efficient and stable red/green/blue (RGB) QE-LEDs. By doping an ionic liquid into QDs, an electrolyte emitting layer (EML) enhances charge injection and transport. Additionally, an insulating layer is placed between the EML and the electron transport layer, suppressing excessive electron leakage. The red QE-LED exhibits a maximum external quantum efficiency (EQE) of 24.2% and a T95 lifetime of 13,100 h at 1000 cd m−2, surpassing previous best red QE-LEDs. The green QE-LED shows an EQE of 20.3% and a T95 lifetime of 14,400 h at 1000 cd m−2. Notably, the blue QE-LED possesses an EQE of 13.5% and a T95 lifetime of 244.5 h at 1000 cd m−2, representing a record stability for solution-processed blue LEDs without light-outcoupling technologies. Furthermore, we develop RGB active-matrix displays, exhibiting excellent stability and uniformity. The results unlock potential opportunities to develop QE-based devices for next-generation high-performance electroluminescence devices and optoelectronic technologies. Quantum-dot electrolyte light-emitting diodes promise new optoelectronics, but efficient green and blue devices remain elusive. Ren et al. developed an inverted, ion-enhanced architecture enabling efficient, stable full-color devices and displays.