Application of Triplet–Triplet Annihilation Upconversion in Organic Optoelectronic Devices: Advances and Perspectives

Abstract

Figure 14. a) EL spectra (inset: photographs of working devices) and b) EQE versus current density (inset: current efficiency-current density curves) for DPA, pyrene, rubrene, and TIPS-pentacene doped poly(9-vinylcarbazole)-based OLEDs. c) Device energy level diagram and d) EQE versus current density curve (inset: current efficiency versus current density) for inverted rubrene-doped F8BT-based OLED device. Reproduced with permission. [83] Copyright 2017, Wiley-VCH.

Observation of Vibrational Phosphorescence Peaks at Room Temperature and Their Impacts on Triplet–Triplet Annihilation

“…[1][2][3][4] This process is also known as triplet fusion, that is, the combination of two triplet excitons into one high-energy singlet. [5,6] The bimolecular nature of TTA In the present work, sensitized room-temperature phosphorescence from the fine structures of T 1 is observed in anthracene-and pyrene-based molecules (PIAnCN and PIMPy, respectively; Figure 1a). [39,40] Observation of the vibrational peaks of 0-0, 0-1, and 0-2 emissions provides us with an opportunity to investigate the dynamics of T 1 directly and assess their respective roles in the TTA process in detail.…”

“…[ 1–4 ] This process is also known as triplet fusion, that is, the combination of two triplet excitons into one high‐energy singlet. [ 5,6 ] The bimolecular nature of TTA facilitates high brightness without efficiency roll‐off. [ 7–12 ] Therefore, this process widely considered to be an alternative mechanism for promoting electroluminescence efficiency.…”

“…[31] The primary challenge in studying triplet states is their dark nature. [6,23,31] The TTA process begins from the fusion of two T 1 . Specifically, one triplet exciton must meet another and undergo bimolecular fusion.…”

Polycyclic aromatic hydrocarbon-based organic semiconductors: ring-closing synthesis and optoelectronic properties

“…The most striking feature of PAH materials is their large conjugated system and unique molecular characteristics, which give them the potential to produce interesting optical, electrical and magnetic properties or to break through the current single performance, such as the integration of high mobility and luminescence, which is crucial for next-generation display technology and electrical-pumped lasers. 149–151 Finally, we believe that as more and more efficient synthetic methods are developed, more PAHs with diverse structures and excellent performances, even artistic, will be achieved, which will present uniqueness in the application of functional devices and research on novel physical properties.…”

Recent Advances in the Photoreactions Triggered by Porphyrin-Based Triplet–Triplet Annihilation Upconversion Systems: Molecular Innovations and Nanoarchitectonics

“…In particular, the regulation of the conjugation length at the β -positions drastically changes the absorption wavelengths of porphyrins, such as Pt/PdOEP, Pt/PdTPTBP, and Pt/PdTPTNP for green light, red light, and near-infrared (NIR) light, respectively ( Figure 2 ). By combining them with annihilators (i.e., DPA and perylene, Figure 2 lists the commonly used annihilators) possessing different emission wavelengths, the porphyrin-based TTA-UC systems can achieve the upconversion of various wavelength ranges including green-to-blue, red-to-blue, NIR-to-blue, and so on, making metalloporphyrins excellent sensitizer candidates for various applications [ 49 ].…”