title: Synthesis and optoelectronic properties of a carbazole-modified platinum(II) complex in polymer light-emitting devices.
abstract: To improve opto-electronic properties and efficiently suppress excimer emission, a phenylpyridine (ppy)-based platinum(II) complex (C(16)OCz-ppy)Pt(acac) was synthesized and characterized, where C(16)OCz-ppy is a 2-phenylpyridine derivative appending a carbazole moiety and three hexadecyloxy methyl units in the parent phenylpyridine, and acac is acetylacetone. This carbazole-modified platinum(II) complex exhibited good thermal stability and three times higher photoluminescent quantum yield than its parent (2-phenylpyridine-C(2),N)(2,4-pentanedionato-O,O)platinum(II) complex [(ppy)Pt(acac)]. Single-emissive-layer polymer light-emitting devices using (C(16)OC(Z)-ppy)Pt(acac) as dopant and a blend of poly(N-vinylcarbazole) and 2-(4-biphenyl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole as host matrix presented a maximum current efficiency of 1.51 cd A(-1), which was 1.5 times higher than that from the (ppy)Pt(acac)-doped device with the same device structure. Little excimer emission and minor aggregation emission were observed in the (C(16)OC(Z)-ppy)Pt(acac)-doped PLEDs at different dopant concentrations and applied voltages. This work indicates that introducing a carbazole and three hexadecyloxy methyl groups into the planar platinum(II) complex can reduce molecular aggregation and excimer emissions, thus resulting in high luminance and stable EL spectra in comparison with the parent (ppy)Pt(acac).
authors: College of Chemistry, Key Lab of Environment-Friendly Chemistry and Application in Ministry of Education, Xiangtan University, Xiangtan, 411105, China.
authors: Jian
authors: J
authors: Luo
authors: Yu
authors: Y
authors: Liu
authors: Danyan
authors: D
authors: Shi
authors: Yafei
authors: Y
authors: Wang
authors: Zhiyong
authors: Z
authors: Zhang
authors: Junting
authors: J
authors: Yu
authors: Gangtie
authors: G
authors: Lei
authors: Qing
authors: Q
authors: Chen
authors: Jianmin
authors: J
authors: Li
authors: Xianping
authors: X
authors: Deng
authors: Weiguo
authors: W
authors: Zhu