[18a-P05-1~32] 12.3 Functional Materials and Novel Devices

English Presentation

[18a-P05-27] Evaluation of Spatial Coherence of the Excited States from Single Crystals of
a Cyano-substituted Thiophene/phenylene Co-oligomer

〇(D)Nanang Adrianto¹, Hitoshi Mizuno^1,2, Andi Marwanti Panre¹, Tomomi Jinjyo¹, Garrek Stemo¹, Hiroyuki Katsuki¹ (1.NAIST, 2.Toyama Pref. Univ.)

Keywords:

Thiophene/phenylene co-oligomer (TPCO) single crystals,Spatial coherence,Excited states

The delocalization area of excited states refers to the spatial extent over which the wavefunctions in these states are distributed in a bulk material. Understanding this excited state is crucial for optimizing the performance of organic electronic and photonic devices. However, it can vary depending on the specific electronic structure of the molecule or material. Thiophene/phenylene co-oligomer (TPCO) single crystals are the most promising candidates owing to their high photoluminescence (PL) quantum efficiency, high carrier mobilities, robustness, and excellent semiconducting properties [1,2] and it is possible to tune their crystal morphologies, crystal structures, and fluorescence properties by changing the crystal growth methods [3]. In this study, we explore the crystal growth conditions using cyano-substituted TPCO, 2,5-bis(4’-cyanobiphenyl-4-yl)thiophene (BP1T-CN), to fabricate one-dimensional rod-like crystals suitable for interference measurements. The lasing properties of the prepared BP1T-CN crystals were also investigated. The blue-emitting (triclinic) were prepared using physical vapor transport, and green-emitting (monoclinic) crystals were prepared by solution-growth methods. These crystals exhibited Fabry–Pérot lasing under optical pumping above threshold excitation densities of 197 and 178 µJ/cm², respectively (Fig. 1). In the presentation, we will report the results of a double-slit experiment to investigate PL interference from two different regimes of excited states in BP1T-CN crystals, which will yield information about their spatial distribution.