A new door for molecular-based organic light-emitting diodes

Multi-3,3′-Bicarbazole-Substituted Arylsilane Host Materials with Balanced Charge Transport for Highly Efficient Solution-Processed Blue Phosphorescent Organic Light-Emitting Diodes

“…Among most functional segments for ideal host materials, carbazole has been widely chosen because of its distinct properties, such as high triplet energy, good solubility, and facile functionalization. − However, it is difficult to obtain bipolar transport abilities by just using carbazole subunits due to their strong hole transport character. A representative bipolar host, bis­(3,5-di­(9H-carbazol-9-yl)­phenyl)­diphenylsilane (SimCP2) with a carbazole moiety as the only functional group, was developed by Chen’s group . Different from most small molecule hosts with highly crystallinity and low thermal stability in the solid state, SimCP2 is completely amorphous and can form highly stable thin films.…”

“…A representative bipolar host, bis(3,5-di(9H-carbazol-9-yl)phenyl)diphenylsilane (SimCP2) with a carbazole moiety as the only functional group, was developed by Chen's group. 34 Different from most small molecule hosts with highly crystallinity and low thermal stability in the solid state, SimCP2 is completely amorphous and can form highly stable thin films. Importantly, it preserves the characteristics of adequate high electron and hole-carrier mobilities of ∼10 −4 cm 2 V −1 s −1 and a sufficiently high triplet state energy of ∼3.01 eV in confining emission energy on FIrpic.…”

Simple model-free estimation of orientation order parameters of vacuum-deposited and spin-coated amorphous films used in organic light-emitting diodes

“…Figure 1 shows the chemical structures of the main OLED materials used in this study including -triphenylbiphenyl-4,4A-diamine) (TPT1), and 2,7-bis(9,9-spirobifluoren-2-yl)-9,9-spirobifluorene (TSBF), which have glass transition temperatures (T g ) of 60, 96, 110, 144, and 231°C, respectively. [9][10][11][12] For each material, we fabricated vacuum-deposited films with thicknesses of 20, 50, and 100 nm on fused silica and Si(100) substrates at a deposition rate of 2 Å=s under a vacuum of <1 × 10 −3 Pa. Spin-coated films were also fabricated on the same types of substrates using solutions of each material in chloroform (15 mg=mL) at spin speeds of 1000, 3000, 5000, and 7000 rpm, followed by mild baking under nitrogen atmosphere for 30 min on a hot plate at a temperature lower than T g : 50°C for TPD and 80°C for the other materials. We measured the absorption spectra of all the sample films on fused silica substrates using a spectrophotometer (Shimadzu UV2450).…”

39.1: Solution Processed Molecular Materials in the Fabrication of Flexible Phosphorescence‐based OLEDs

“…Moreover, due to the requirement of high triplet state energy, host materials suitable for blue phosphorescence dopants is not common, let along its solution processing. As a continuing effort in quest of adequate host material for blue phosphorescence dopant, [1][2][3][4][5][6] we have successfully developed a new small molecule-based host material SimCP2 (Scheme 1) for solution processing. More significantly, non-polymer-based host material SimCP2 provides dopant FIrpic one of the first flexible, blue phosphorescence OLEDs with solution processed fabrication and sufficiently high electroluminescence efficiency.…”