An exciplex could be formed by blending a selected hole-transporting material (HTM)/electron-transporting material (ETM) pair, and the corresponding energy band gap is roughly determined by the energy difference between the lowest unoccupied molecular orbital (LUMO) of the ETM and the highest occupied molecular orbital (HOMO) of the HTM. In this study, three HTM/ETM combinations are adopted to generate blue, green, and red exciplexes, allowing us to design precise device architectures for the fabrication of exciplex-based white OLEDs (WOLEDs) with daylight-like emissions. The CIE coordinates of this WOLED varied close to the Planckian locus as the biases increase, with a high color rendering index of about 96. This high performance suggests this exciplex-based WOLED can provide high-quality white-light illumination. Photoluminance and lifetime measurements of the exciplex behavior of the HTM/ETM combinations indicate that the HTM and ETM selected should possess higher triplet energy bandgaps than those of their corresponding exciplex to avoid energy loss.

Download full-text PDF

Source
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC9085475PMC
http://dx.doi.org/10.1039/c8ra04986fDOI Listing

Publication Analysis

Top Keywords

exciplex-based white
8
molecular orbital
8
htm/etm combinations
8
pure exciplex-based
4
white organic
4
organic light-emitting
4
light-emitting diodes
4
diodes imitation
4
imitation daylight
4
daylight emissions
4

Similar Publications

An exciplex, which is composed of electron donor and acceptor molecules and formed by intermolecular charge transfer, is an excited-state species that is able to emit light or transfer its energy to a lower-energy emitter. In reported exciplex-based organic light-emitting diodes (OLEDs), their working mechanism is to generate exciplexes either in the bulk emitting layer (bulk exciplex) or at its interface with an electron transport layer (interface exciplex); both types give promising device performance. Here, we propose a novel strategy of creating both types of exciplexes simultaneously (dual exciplexes) for the generation of more exciplexes for better device performance as indicated in the improved photoluminescence quantum yield (PLQY).

View Article and Find Full Text PDF

Capability of exciplex energy transfer through a spacer was investigated using three exciplex-forming solid mixtures which contained the well-known electron accepting 2,4,6-tris[3-(diphenylphosphinyl)phenyl]-1,3,5-triazine and appropriately designed bipolar cyanocarbazolyl-based derivatives functionalized by attachment of carbazolyl, acridanyl or phenyl units. These novel cyanocarbazolyl-based derivatives were used as both the spacer and exciplex-forming donor. Efficient organic light-emitting diodes with electroluminescence in cyan-yellow region and maximum external quantum efficiency of up to 7.

View Article and Find Full Text PDF

An exciplex could be formed by blending a selected hole-transporting material (HTM)/electron-transporting material (ETM) pair, and the corresponding energy band gap is roughly determined by the energy difference between the lowest unoccupied molecular orbital (LUMO) of the ETM and the highest occupied molecular orbital (HOMO) of the HTM. In this study, three HTM/ETM combinations are adopted to generate blue, green, and red exciplexes, allowing us to design precise device architectures for the fabrication of exciplex-based white OLEDs (WOLEDs) with daylight-like emissions. The CIE coordinates of this WOLED varied close to the Planckian locus as the biases increase, with a high color rendering index of about 96.

View Article and Find Full Text PDF

Single-Phase White-Light-Emitting and Photoluminescent Color-Tuning Coordination Assemblies.

Chem Rev

September 2018

Ministry of Education (MOE) Laboratory of Bioinorganic and Synthetic Chemistry, Lehn Institute of Functional Materials, School of Chemistry , Sun Yat-Sen University, Guangzhou 510275 , China.

Metal-organic complexes assembled from coordinative interactions are known to be able to display a wide range of photoluminescent behaviors benefiting from an extensive number of metal ions, organic linkers, and inclusion guests, depending on the multifaceted nature of their chemical structures and photophysical properties. In the past two decades, the white-light-emitting (WLE) and photoluminescent color-tuning (PLCT) materials based on the single-phase metal-organic coordination assemblies have merited particular attention and gained substantial advances. In this review, we give an overview of recent progress in this field, placing emphasis on the WLE and PLCT properties realized in the single-phase materials, which covers the origin, generation, and manipulation of different types of photoluminescence (PL) derived from ligand-centered (LC), metal/cluster-centered (MC or CC), excimer/exciplex-based (EX), metal-to-ligand or ligand-to-metal charge-transfer-based (MLCT or LMCT), or guest-included emissions.

View Article and Find Full Text PDF

The investigation of the mechanisms of mechanochromic luminescence is of fundamental importance for the development of materials for photonic sensors, data storage, and luminescence switches. The structural origin of this phenomenon in phosphorescent molecular systems is rarely known and thus the formulation of structure-property relationships remains challenging. Changes in the M-M interactions have been proposed as the main mechanism with d coinage metal compounds.

View Article and Find Full Text PDF

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!