Effects of Position of Exciton-Blocking Layer on Characteristics of Blue Phosphorescent Organic Light-Emitting Diodes

Effect of Carrier-Transporting Layer on Blue Phosphorescent Organic Light-Emitting Diodes

“…Figure 4c shows the spectra, where blue-shift in the emission color was observed in device F. The shoulder peaks of 470 nm were obvious due to RZ moving toward the cathode side. Similarly, this can be explained by the microcavity effect due to TAPC facilitating a superior hole transport, resulting in a wider RZ, extending to the TAZ layer, and a short optical length from RZ to the cathode as illustrated in Figure 4d [36]. Therefore, the mCP emission was eliminated by applying a faster HTL, but another CTL emission from TAZ occurred as is shown in the inset of Figure 4c.…”

“…The main EL peak was similar, but there was a different intensity in the shoulder EL peak of 550 nm. Devices A and B exhibited less shoulder emission than device C did, which was ascribed to the micro-cavity effect induced by different electron mobility of ETL generating the different width of recombination zone (RZ) [35,36]. A schematic model is illustrated in Figure 2d, where RZ is displayed with a varied width created by TAZ, TmPyPB, DPPS.…”

Effects of Gold-Nanoparticle Surface and Vertical Coverage by Conducting Polymer between Indium Tin Oxide and the Hole Transport Layer on Organic Light-Emitting Diodes

“…Note that the use of 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BPhen) material, which has faster electron mobility than Alq 3 , − as an ETL may yield superior device performance because of its superior charge balance and energy band alignment. Therefore, this different device structure will be studied in a future investigation in order to optimize the device performance.…”

“…Therefore, this different device structure will be studied in a future investigation in order to optimize the device performance. The charge balance of holes and electrons in the EML is quite critical to the device performance, and it can be varied by adjusting the carrier mobility at the HTL and ETL. − …”

“…The more Au-NPs that are aggregated in the PEDOT:PSS, the greater the optical enhancement that can occur. Likewise, the current densities are altered by the carrier trapping at the Au-NP sites; thus, a small shift in the recombination zone could be caused by the microcavity effect. − Note that, although the Au-NPs were enclosed in the PEDOT:PSS, it was not possible to observe a plasmon-derived resonance effect, because little overlap occurred between the absorption of the Au-NPs and the PL of the emitters.…”