Spiro-based hole-transporting materials utilized in green perovskite quantum dot light-emitting diodes with high luminance

Herein, two new spiro-cored hole-transporting materials (HTMs), termed HT1 and HT2, are designed and synthesized, breaking the symmetry of the classical HTM, spiro-OMeTAD, by introducing benzo[d]imidazole with diverse electron characteristics of two nitrogen atoms to improve their hole-transporting properties. Both HT1 and HT2 exhibited excellent thermal stability with glass transition temperatures (Tg) of 162 and 197 & DEG;C, respectively, and good hole transport capability with hole mobilities of 8.26 x 10-5 and 1.08 x 10-4 cm2 V-1 s-1, respectively. When utilized in green perovskite quantum dot light-emitting diodes (Pe-QLEDs), the devices achieved low turn-on voltages of 3.0 and 2.8 V, maximum external quantum efficiency (EQEmax) of 7.6 and 6.7% and high maximum luminance of 45 056 and 46 382 cd m-2, respectively. The excellent hole-transporting properties and great device performance show that HT1 and HT2 are promising HTMs for Pe-QLEDs. Pe-QLEDs based on two spiro-cored HTMs achieved high brightness of 45 056 and 46 382 cd m-2, respectively.