1. Department of Macromolecular Science and Engineering, Kyoto Institute of Technology, Sakyo, Kyoto, Japan;2. Advanced Materials Research Lab, NTT Institute of Hi‐technology, Nguyen Tat Thanh University, Ho Chi Minh City, Viet Nam;3. Faculty of Materials Science and Engineering, Kyoto Institute of Technology, Sakyo, Kyoto, Japan
Abstract:
A perylene bisimide derivative of N,N′‐diisopropylphenyl‐1,6,7,12‐tetrachloroperylene‐3,4,9,10‐tetracarboxyl bisimide (PBI) is synthesized and used as a sensitizer for a photorefractive (PR) polymer composite. Small amount (0.1 wt%) of PBI sensitizer gives the maximum PR performance of composite based on poly(4‐(diphenylamino)benzyl acrylate) (PDAA) (45 wt%), 2‐(4‐(azepan‐1‐yl)benzylidene)malononitrile (35 wt%), and (4‐(diphenylamino)phenyl)methanol (24.9 wt%). High external diffraction efficiency of 49%, response time of 47 ms, and sensitivity of 28 cm2 J?1 are obtained under an applied electric field of 40 V μm?1 at writing beam of 532 nm. PBI sensitizer effectively forms a charge‐transfer complex with PDAA, which favors the generation of the charge carriers followed by the space‐charge formation. Furthermore, low PBI concentration contributes to low absorption coefficient at 532 nm, which leads to better PR performance.
