Elastic Self‐Doping Organic Single Crystals Exhibiting Flexible Optical Waveguide and Amplified Spontaneous Emission

Abstract

Organic crystals are generally brittle and tend to crack under applied stress. Doped organic crystals are even more brittle because of lattice defects. Herein, the first doped organic crystals 1d@2d, which display elastic bending ability under applied stress, are reported. Moreover, the potential applications of elastic-doped crystals 1d@2d in flexible optoelectronics are impressively demonstrated. The elastic crystals 1d@2d with high quality and large size are crystalized by a simple and unique "self-doping" process, which is a regular solution evaporation of crude product 1d (2,5-dihydro-3,6-bis(octylamino)terephthalate) containing a minute amount of 2d (3,6-bis(octylamino)terephthalate) as the oxidized byproduct. The host 1d is easily crystallized to form elastic crystals but is nonfluorescent, while the guest 2d has poor crystallinity and is highly emissive. The doping approach integrates the advantages of both 1d and 2d, and thus endows doped crystals 1d@2d with good elasticity as well as intense orange fluorescence. Taking these advantages, the application potentials of these doped crystals 1d@2d are evaluated by measuring optical waveguide and amplified spontaneous emission in both the straight and bent states.

Is a Bent Crystal Still a Single Crystal?

“…[25][26][27][28][29][30] Single-crystal X-ray diffraction analyses were performed on elastic cocrystals of caffeine and 4-chloro-3-nitrobenzoic acid to evaluate the structural integrity and crystallinity in the bent region. [25][26][27][28][29][30] Single-crystal X-ray diffraction analyses were performed on elastic cocrystals of caffeine and 4-chloro-3-nitrobenzoic acid to evaluate the structural integrity and crystallinity in the bent region.…”

2,5‐Dimethoxybenzene‐1,4‐dicarboxaldehyde: An Emissive Organic Crystal and Highly Efficient Fluorescent Waveguide

“…The α was thus calculated to be 0.00120 dB/μm (Figure d). It is note that α value is relatively high in those of reported materials . The loss coefficient and red‐shift are mainly affected by the reabsorption during the propagation of the light along the crystal .…”

“…It is note that α value is relatively high in those of reported materials . The loss coefficient and red‐shift are mainly affected by the reabsorption during the propagation of the light along the crystal . In the region of short wavelength, the emission band overlaps with the absorption band of the crystalline powder and the excitation spectrum of the crystal (Figure a), which is harmful for the light propagation and results in a high loss coefficient.…”

Ist ein gebogener Kristall immer noch ein Einkristall?

“…[25][26][27][28][29][30] Einkristall-Rçntgenbeugungsanalysen wurden an elastischen Kokristallen aus Coffein und 4-Chlor-3-nitrobenzoesäure durchgeführt, um die strukturelle Integritätu nd Kristallinitäti mg ebogenen Bereich zu bewerten. [25][26][27][28][29][30] Einkristall-Rçntgenbeugungsanalysen wurden an elastischen Kokristallen aus Coffein und 4-Chlor-3-nitrobenzoesäure durchgeführt, um die strukturelle Integritätu nd Kristallinitäti mg ebogenen Bereich zu bewerten.…”