title: Fast responsive and highly efficient optical upconverter based on phosphorescent OLED.
abstract: In this work, an organic-inorganic hybrid optical upconverter that can convert irradiated 980 nm IR light to 510 nm green phosphorescence sensitively was fabricated and studied. fac-Tris(2-phenylpyridine) iridium (Ir(ppy)3) doped 4,4'-bis(N-carbazolyl)-1,1'-biphenyl (CBP) was used as emitting layer in the phosphorescent organic light-emitting diode (OLED) unit. The upconverter using a phosphorescent OLED as display unit can achieve a higher upconversion efficiency and a low power consumption when compared with the one using fluorescent. An upconversion efficiency of 4.8% can be achieved for phosphorescent device at 15 V, much higher than that of fluorescent one (2.0%). The upconverter's transient optical and electric response to IR pulse were also investigated for the first time. The response time was found to be influenced by IR intensity and applied voltage. It has a response time as short as 60 μs. The rapid response property of the upconverter makes it feasible to be applied to high-speed IR imaging systems.
authors.affiliation: Key Laboratory of Semiconductor Materials Science, Institute of semiconductors, Chinese Academy of Sciences , Beijing, China.
authors.forename: Xinbo
authors.initials: X
authors.lastname: Chu
authors.forename: Min
authors.initials: M
authors.lastname: Guan
authors.forename: Litao
authors.initials: L
authors.lastname: Niu
authors.forename: Yiping
authors.initials: Y
authors.lastname: Zeng
authors.forename: Yiyang
authors.initials: Y
authors.lastname: Li
authors.forename: Yang
authors.initials: Y
authors.lastname: Zhang
authors.forename: Zhanping
authors.initials: Z
authors.lastname: Zhu
authors.forename: Baoqiang
authors.initials: B
authors.lastname: Wang
keywords: 42.79.Pw; 85.60.Bt; 85.60.Jb; OLED; fast response; infrared photo detector; optical upconverter; organic−inorganic hybrid device; phosphorescent