Performance Optimization of Solution-processed QLEDs with CuSCN Hole Injection Layer

Abstract Quantum dot light-emitting diodes (QLEDs) are promising for future display and lighting technologies due to their excellent optical properties and ease of fabrication.However traditional hole injection materials like PEDOTPSS limit QLED performance.This study explores copper thiocyanate (CuSCN) as the hole injection layer paired with CdSe/ZnS green quantum dots and various hole transport layers (HTLs) such as PVK and Poly-TPD.We assessed the optoelectronic properties of these devices under both alternating current (AC) and direct current (DC) conditions.Our results reveal that the energy level barrier between CuSCN and PVK leads to charge trapping which adversely affects performance.In contrast Poly-TPD with its higher hole mobility and shallower HOMO energy lev el alleviates charge trapping significantly enhancing brightness and current efficiency to peak values of 132 075 cd/m and 15. 6 cd/A respectively.This research provides insights into the charge trapping mechanism at the CuSCN/HTL interface highlighting CuSCN as a viable alternative to PEDOTPSS for improving QLED efficiency.Key words copper thiocyanate (CuSCN) quantum dot light-emitting diodes (QLEDs) hole injection trapped charge alternating current