Advanced HIL strategies in QLEDs: V2O5 and PEDOT:PSS dual-layer for charge balance and electron leakage prevention

Abstract

Quantum dot light emitting devices (QLEDs) show promise for displays, with polyethylenedioxythiophene:polystyrene (PEDOT:PSS) commonly used as a hole injection layer (HIL) due to its high conductivity and work function. However, PEDOT:PSS-based QLEDs face an energy barrier, reducing efficiency. Herein, in this work, we used the rapid thermal annealing (RTA) process to improve the conductivity by controlling the RTA processing time which reduced the interfacial resistance. This improves charge balance and long-term stability by preventing electron leakage. The optimized V₂O₅/PEDOT:PSS-based QLED, with an EQE of 18%, CE of 77 cd A⁻¹ and maximum luminance of 23 242 cd m⁻², outperforms the PEDOT:PSS-based counterpart. This highlights the strategic superiority of V₂O₅ HIL in our QLED.