Effect of SiO2/Si3N4 dielectric distributed Bragg reflectors (DDBRs) for Alq3/NPB thin-film resonant cavity organic light emitting diodes

High-Performance White Organic Light-Emitting Diodes Using Distributed Bragg Reflector by Atomic Layer Deposition

“…In OLED microcavities, the active layers of OLEDs are composed by the optimal medium between two mirrors [13]. The most common OLED microcavity architectures contain (i) two similar metal mirrors with different thicknesses, where one mirror is only partially reflective, while the other mirror is almost thoroughly reflective and (ii) one mirror serves as a dense dielectric distributed Bragg reflector (DBR), generally consisting of a periodic stack of SiO 2 /TiO 2 or SiO 2 /SiN as well as other mirror materials with a low work function metal [14,15].…”

Enhanced organic light-emitting diode based on a columnar liquid crystal by integration in a microresonator

“…The present work describes OLED based on a columnar perylene derivative that shows enhanced electroluminescence intensity and reduced emission linewidth owing to a microcavity ( Figure 1). Other authors have shown that the resonant cavity-enhanced (RCE)-LED approach that is well-known from inorganic LED [33,34] can be readily applied to OLED [35,36]. The columnar mesophase appears at elevated temperatures [31,32] so that annealing in the respective temperature range can be used to obtain a uniform alignment, which is preserved in the solid phase appearing at room temperature and promotes a large charge carrier mobility.…”

“…Previous studies [30][31][32] have revealed the discotic liquid crystalline compound perylene-3,4,9,10tetracarboxylic-tetraethylester (PTCTE) to be both a decent semiconductor and an OLED emitter with very high luminescence quantum yield. Depending on the distance of the mirrors, this cavity may act as either a monomode resonator, which leads to a narrow emission linewidth [35], or a multimode resonator, which can be used to generate white light [36]. Other authors have shown that the resonant cavity-enhanced (RCE)-LED approach that is well-known from inorganic LED [33,34] can be readily applied to OLED [35,36].…”

“…The columnar mesophase appears at elevated temperatures [31,32] so that annealing in the respective temperature range can be used to obtain a uniform alignment, which is preserved in the solid phase appearing at room temperature and promotes a large charge carrier mobility. Other authors have shown that the resonant cavity-enhanced (RCE)-LED approach that is well-known from inorganic LED [33,34] can be readily applied to OLED [35,36]. The emitted luminescence intensity can be enhanced by embedding the organic layers between a Bragg mirror and a transparent electrode on one side and a metal layer on the opposite side, which forms a Fabry-Perot cavity.…”

“…The emitted luminescence intensity can be enhanced by embedding the organic layers between a Bragg mirror and a transparent electrode on one side and a metal layer on the opposite side, which forms a Fabry-Perot cavity. Depending on the distance of the mirrors, this cavity may act as either a monomode resonator, which leads to a narrow emission linewidth [35], or a multimode resonator, which can be used to generate white light [36]. Standard OLED devices make use of a transparent substrate, on which a transparent anode (made of indium tin oxide, ITO), the active organic layers, and a metal cathode are deposited.…”