@article{Zhang2025, 
author = {Heng Zhang and Zhe Wang and Dawei Yang and Bingsuo Zou and Shuming Chen},
title = {PIN quantum-dot LEDs with enhanced efficiency and stability enabled by bulk-heterojunction hole transport layer},
year = {2025},
journal = {Nano Research},
volume = {18},
number = {2},
pages = {94907155},
keywords = {quantum dots, light-emitting diodes, hole transport layer, trilayer, p-type/intrinsic/n-type (PIN)},
url = {https://www.sciopen.com/article/10.26599/NR.2025.94907155},
doi = {10.26599/NR.2025.94907155},
abstract = {Although quantum-dot light-emitting diodes (QLEDs) can exhibit high efficiency and long lifetime, the realization of QLEDs-based displays remains challenging due to their complex multilayer architectures and the use of unstable poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) hole injection layer (HIL). Here, we develop a novel trilayer p-type/intrinsic/n-type (PIN) QLED with only three functional layers: PTAA:TFB:F4-TCNQ (PTAA: poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine]; TFB: poly[(9,9-dioctylfluorenyl-2,7-diyl)-co-(4,4'-(N-(4-sec-butylphenyl)diphenylamine)]; F4-TCNQ: 2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane) bulk-heterojunction (BHJ) hole transport layer (HTL), quantum-dot emitting layer, and ZnMgO electron transport layer. Due to well-matched energy level, increased hole transport path from PTAA to TFB, and improved hole density and enhanced hole mobility of the PTAA:TFB:F4-TCNQ BHJ HTL, the resultant trilayer PIN QLED exhibits a high external quantum efficiency (EQE) of 25.1% and an impressive peak brightness of 382,600 cd/m2, which are significantly higher than those of the control QLED. Moreover, the trilayer PIN QLED also shows a 1.94-fold longer operational lifetime than control QLED due to the improved device performance, reduced charge accumulation, and removal of unstable PEDOT:PSS. The developed trilayer PIN QLED, with fewer functional layers and better stability, could promote the practical application of QLED in displays and solid-state lighting.}
}