Presentation Information
[22a-P02-26]Characterization of vapor-phase- and solution-grown crystals of cyano group-substituted thiophene/phenylene co-oligomer
〇(D)Nanang Adrianto1, Hitoshi Mizuno1, Andi Marwanti Panre1, Tomomi Jinjyo1, Hiroyuki Katsuki1 (1.NAIST)
Keywords:
Thiophene/phenylene co-oligomer (TPCO) single crystals,Vapor-phase- and solution-grown crystals,Lasing
Thiophene/phenylene co-oligomer (TPCO) single crystals of light-emitting π-conjugated compounds have attracted attention for laser media owing to their high photoluminescence (PL) quantum efficiency, high carrier mobilities, robustness, and excellent semiconducting properties [1, 2]. Jinjyo et al. have recently reported that crystal morphologies, crystal structures, and fluorescence properties can be controlled by changing the crystal growth methods using 5,5’-bis(4’-cyanobiphenyl-4-yl)-2,2’-bithiophene (BP2T-CN) which is a kind of cyano group-substituted TPCO [3]. In the present study, we explored crystal growth conditions using the similar cyano-substituted TPCO, BP1T-CN, to fabricate one-dimensional rod-like crystals suitable for fluorescence interferometry and lasing measurements. The PL properties of the prepared BP1T-CN crystals were also investigated. Vapor-grown crystals were prepared using a physical vapor transport method. Solution-grown crystals were prepared by slow cooling from 120°C to 40°C in N,N-dimethylformamide (DMF). PL spectrum of the vapor-phase-grown crystal exhibit-emission bands around 496 and 526 nm which are assigned to vibrational of the 0-1 and 0-2 progressions, as shown in Fig. 1(b). In the solution-grown crystal, emission bands appear at approximately 525 and 559 nm corresponding to 0-1 and 0-2 vibronic progressions, respectively. Rod-like crystals were obtained by both vapor-phase and solution-growth methods, but the crystal obtained by the solution-growth method showed a 29 nm red-shift in the emission band. Possible causes of this red-shift include the formation of crystal polymorphs, impurities, and defect levels. In the presentation, we will report the results of X-ray diffraction, elemental mapping, and mass spectrometry of both crystals, as well as the results of optical properties.