Gao, Mile; Mai, Van T. N.; Jang, Junhyuk; Ranasinghe, Chandana Sampath Kumara; Chu, Ronan; Burn, Paul L.; Gentle, Ian R.; Pivrikas, Almantas; Shaw, Paul E. published their research in Journal of Materials Chemistry C: Materials for Optical and Electronic Devices in 2021. The article was titled 《Effect of dendron structure on the luminescent and charge transporting properties of solution processed dendrimer-based OLEDs》.COA of Formula: C12H7Br2N The article contains the following contents:
The photophys. and charge transport properties of neat and blend films of fac-tris[2-phenylpyridinato-C2,N]iridium(III) [Ir(ppy)3]-cored light-emitting dendrimers and tris(4-carbazoyl-9-ylphenyl)amine (TCTA)-based hosts, with each combination having the same first generation dendrons were measured and compared. The first generation dendrons were composed of bis(fluorenyl)carbazolyl with Pr surface groups, or biphenyl with 2-ethylhexyloxy or t-Bu surface groups. Dendronisation of the emitter and host was found to decrease the energy transfer efficiency from the host to the guest relative to an evaporated Ir(ppy)3:TCTA blend film, with the blend composed of materials with biphenyl dendrons and t-Bu surface groups having the largest decrease. The hole mobilities of the solution processed neat and blend layers were found to be 1-2 orders of magnitude lower than those of the equivalent evaporated films. The blend film containing the host and dendrimer with first generation biphenyl dendrons and 2-ethylhexyloxy surface groups had the highest photoluminescence quantum yield (PLQY), comparable to evaporated Ir(ppy)3:TCTA-based films but the lowest hole mobility (≈10-8 cm2 V-1 s-1). In contrast, the blend with the dendrimers composed of the bis(fluorenyl)carbazolyl dendrons with Pr surface groups had a low PLQY but higher hole mobility. It was found for the combinations of these solution processable materials that the hole mobility of the blend film was the limiting factor in OLED performance. Devices containing an emissive layer of the materials with the bis(fluorenyl)carbazolyl dendrons with Pr surface groups (11 mol percent of the emitter) had a PLQY of 40.8% but the highest external quantum efficiency of 10.0 ± 0.4%, reaching a maximum luminance of almost 10 000 cd m-2. In the experimental materials used by the author, we found 3,6-Dibromo-9H-carbazole(cas: 6825-20-3COA of Formula: C12H7Br2N)
3,6-Dibromo-9H-carbazole(cas: 6825-20-3) is used as a pharmaceutical intermediate, and also an important intermediate of synthesizing optoelectronic materials. It has been used as a reagent in the synthesis of P7C3-A20 which is a potent neuroprotective agent.COA of Formula: C12H7Br2N
Referemce:
Bromide – Wikipedia,
bromide – Wiktionary