Polarized measurements of spectrally narrowed emissions from a single crystal of a thiophene/phenylene co-oligomer

Abstract

The spectrally narrowed emissions ͑SNE͒ from a flat single crystal of a thiophene/phenylene co-oligomer were investigated in a series of polarized measurements. The SNE spectra comprise of two major lines occurring at 507 and 514 nm. Of these, the former line effectively causes the emission gain narrowing by the pulse laser excitation polarized along the c axis. The intensity of the SNE is nearly isotropic with the radial directions along the flat crystal plane paralleling the bc plane. The SNE is strongly polarized along the a axis with its emission polarization ratio of the a axis to the b axis being 16.7. These polarized SNEs can be understood by the upright configuration of the molecular long axis paralleling the a axis.

Laser oscillation in a highly anisotropic organic crystal with a refractive index of 4.0

“…The experimental setup for the emission measurements is similar to the previous study. 15 Unlike the previous study, however, we used an optical parametric oscillator ͑LOTIS TII, LT-2215OPO͒ pumped with a Nd:yttrium aluminum garnet laser ͑LOTIS TII, LS-2137͒ for the excitation light source. The excitation wavelength, pulse duration, and pulse repetition rate were 420 nm, 16 ns, and 10 Hz, respectively.…”

Organic Single‐Crystalline Semiconductors for Light‐Emitting Applications: Recent Advances and Developments

“…The high polarization contrast of about 0.93 indicated a nearly linearly polarized emission. Moreover, the same phenomenon and even polarized spectrally narrowed emission have also been discovered in TPCO crystals as a consequence of their nearly upright configuration of molecules against the crystal plane …”

Refractive Index along the Molecular Long Axis of an Orthorhombic Thiophene/Phenylene Co-Oligomer Crystal

“…Meanwhile, the crystal of BP1T-OMe [10], one of TPCO materials, is orthorhombic [11], and has shown strongly polarized spectrally-narrowed emission (SNE) [12]. This polarized SNE was attributed partly to the upright configuration of the molecular long axis exactly parallel to the crystal long axis.…”