Molecular hosts for triplet emitters in organic light-emitting diodes and the corresponding working principle

Abstract

This paper summarizes the mechanism and routes for excitation of triplet emitters in dopant emission based phosphorescent organic light-emitting diodes (PhOLEDs), providing a comprehensive overview of recent progress in molecular hosts for triplet emitters in PhOLEDs. Particularly, based on the nature of different hosts, e.g., hole transporting, electron transporting or bipolar materials, in which the dopant emitters can be hosted to generate phosphorescence, the respective device performances are summarized and compared. Highlights are given to the relationships among the molecular structure, thermal stability, triplet energy, carrier mobility, molecular orbital energy level and their corresponding device performances. phosphorescent organic light-emitting diodes (OLEDs), working principle, electrophosphorescence, hosts, triplet emitter

A Bipolar and Small Singlet‐Triplet Splitting Energy Host with Triplet Energy Lower Than a Blue Phosphor for Phosphorescent OLEDs in Panchromatic Range

“…It can be explained by the higher energy band-gap (E g ) of TCPZ than CBP. 16 efficiencies at lower (3% and 6%) and higher (12%) doping concentrations are mainly due to the insufficient luminescent centers and high concentration quenching, [30] as well as triplet-triplet exciton annihilation in FIrpic at high doping concentration. For instance, device R showed maximum efficiency of 9.3 cd•A 1 (13.2%), while those in our previous work are 8.3%.…”

P‐173: New Triazine Derived Hosts for Next Generation Phosphorescent OLEDs with Enhanced Lifetime and Stability

“…3. ITO / EHI609 (70 nm) / NPB (7 nm) / TCTA (5 nm) / 7% Ir(ppy) 3 Table 2 summarizes the electroluminescent performances of the devices A-D at 1000nits. The operation driving voltages at 1000nits, using PH1-PH3 were 4.29, 4.55 and 3.90 V, almost 3V lower compared to that of CBP; Also, the turn on voltages were in the range of 3 to 3.5 V for the newly developed hosts, whereas CBP requires a minimum of 5V (Fig.…”

“…Phosphorescent OLED technology is one of the best ways to lower the power consumption of OLEDs, as they provide better quantum efficiency than fluorescent OLEDs [2]. Much work has been done to improve the luminance efficiency of phosphorescent OLEDs through the development of materials and device structures [3,4]. One of the strategies to achieve highly efficient Phosphorescent OLEDs is doping phosphorescent emitters of transition metal complexes into suitable hosts, thereby suppressing concentration quenching and triplet-triplet annihilation.…”

P-204L:Late-News Poster: Highly Efficient, Long-Lifetime and Deep-Blue Emissive Materials for OLED Display and Lighting Applications

“…Extensive research efforts have been conducted to improve the efficiency, color stability, power consumption and lifetime characteristics [2]. One of the bottlenecks in the OLED technology is power consumption compared to the LCD/LED technologies.…”