High-Brightness and Ultra-Long-Lifetime Spin Quantum Dot Light-Emitting Diodes Enabled by Efficient Injection of Spin-Polarized Holes Through a Hybrid Hole Transport Layer.

Spin-polarized quantum dot light-emitting diodes (spin-QLEDs) offer a package solution for advanced photonic applications, such as quantum information processing. However, the performance of these devices is threatened by integration of chiral layers due to greatly compromised interfacial hole transport and deteriorate film morphology. In this work, a hybrid hole transport layer (HTL) engineering strategy is proposed to simultaneously tackle the two key issues. On one hand, enhanced surface hydrophilicity of the HTL enables the growth of a high-quality chiral perovskite layer as a spin filter. On the other hand, tri-channel hole transport mechanism is first unraveled theoretically and experimentally to realize high-mobility pathways, stepwise injection, and bypass the resistive limitations of traditional HTL. The resulting spin-QLEDs demonstrated an ultralong T50 lifetimes at 100 cd/m2 to be 3968.9 h which is orders of magnitude higher than other reports. Moreover, the spin-QLEDs exhibit a recorded luminance of 14,370 cd/m2 for red-light-emitting devices, alongside an external quantum efficiency of 6.68% and a circularly polarized electroluminescence asymmetry factor (gCP-EL) of 0.026. This hybrid HTL architecture offers a reliable route toward long-lived and high-brightness spin-optoelectronic devices.