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High-performance blue and green electrophosphorescence achieved by using carbazole-containing bipolar tetraarylsilanes as host materials
| Content Provider | Semantic Scholar |
|---|---|
| Author | Gong, Shaolong Chen, Yong-Hua Zhang, Xin Cai, Peijun Zhong, Cheng Ma, Dongge Qin, Jingui Yang, Chuluo |
| Copyright Year | 2011 |
| Abstract | A series of carbazole-containing tetraarylsilane compounds, namely p-BISiPCz (1), m-BISiPCz (2), p-OXDSiPCz (3) and m-OXDSiPCz (4) were designed and synthesized by incorporating electron-donating carbazole and electron-accepting benzimidazole or oxadiazole into one molecule via a silicon-bridge linkage mode. Their thermal, photophysical and electrochemical properties can be finely tuned through the different groups and linking topologies. The di-para-position compounds 1 and 3 display higher glass transition temperatures and slightly lower triplet energies than their di-meta-position isomers 2 and 4, respectively. The four compounds exhibit similar HOMO levels (5.60–5.63 eV), while the LUMO level of 3 (2.36 eV) is slightly lower than that of 4 (2.28 eV). The silicon-interrupted conjugation of the electron-donating and electron-accepting segments endows these materials with relative high triplet energies, good thermal and morphological stability, and bipolar transporting ability. For FIrpic-based blue PhOLEDs, the di-meta-position compounds 2 and 4 display better device performances than their di-para-position analogues 1 and 3, respectively. Device B using 2 as the host exhibits the best performance with a maximum current efficiency of 29.3 cd A−1, a maximum power efficiency of 19.8 lm W−1, and a maximum external quantum efficiency of 11.4%. Green phosphorescent devices using (ppy)2Ir(acac) as guest and 1–4 as hosts show excellent EL performances with maximum external quantum efficiencies of 18.3–22.2%. Remarkably, device H hosted by 4 still exhibits an external quantum efficiency of 19.4% at the extremely high luminance of 10 000 cd m−2. These efficiencies are significantly higher than those of blue and green control devices using mCP as host, respectively. |
| Starting Page | 11197 |
| Ending Page | 11204 |
| Page Count | 8 |
| File Format | PDF HTM / HTML |
| DOI | 10.1039/C1JM11208B |
| Volume Number | 21 |
| Alternate Webpage(s) | http://www.rsc.org/suppdata/jm/c1/c1jm11208b/c1jm11208b.pdf |
| Alternate Webpage(s) | https://doi.org/10.1039/C1JM11208B |
| Language | English |
| Access Restriction | Open |
| Content Type | Text |
| Resource Type | Article |
