Highly Efficient Organic Blue Electroluminescent Materials and Devices with Mesoscopic Structures

Abstract

Due to the difficulty in achieving high efficiency and high color purity simultaneously, blue emission is the limiting factor for the performance and stability of OLEDs. Since 2003, we have been working on organic light-emitting diodes (OLEDs), especially on blue light. After a series of molecular designs, novel strategies have been proposed from different aspects. At first, highly efficient deep blue emission could be achieved through molecular design with highly twisted structure to suppress fluorescence quenching and redshift. Deep blue emitters with high efficiency in solid state, a twisted structure with aggregation induced emission (AIE) characteristics was incorporated to inhibit molecular aggregation, and triplet-triplet fusion (TTF) and hybridized localized charge transfer (HLCT) were adopted to increase the ratio of triplet exciton used. Secondly, a highly efficient blue OLED could be achieved through improving charge transport. New electron transport materials (ETMs) with wide band gap were developed to control charge transport balance in devices. Thirdly, a highly efficient deep blue emission could be achieved through a mesoscopic structure of out-coupling layer. A mesoscopic photonic structured organic thin film was fabricated on the top of metal electrode by self-aggregation in order to improve the light out-coupling efficiency.

Recent Advances in the Optimization of Organic Light‐Emitting Diodes with Metal‐Containing Nanomaterials

“…Moreover, light‐scattering effect can obviously occur when metallic nanomaterials are introduced into OLEDs, which can significantly alleviate the optical loss. Up to now, many review papers have been published mainly focusing on the development of organic functional materials and device structures of OLEDs, however, there is still no comprehensive overview on the optimization of OLEDs with the metal‐containing nanomaterials, which is very attractive for both academic research and commercial application of high performance OLEDs and other optoelectronic devices . In this review, the fundamental knowledge of OLEDs and metallic nanomaterials were firstly introduced.…”