Аннотация:Emissive materials that radiate polarized light are in high demand for a broad variety of light-emitting electronic devices. In organic light-emitting devices—light-emitting diodes and transistors—highly polarized emission from the device surface, the surface emission, can be achieved by the in-plane co-linear orientation of molecular transition dipole moments (TDMs) in the device active layer. Furthermore, such a TDM arrangement strongly alleviates the waveguiding effect, enhancing the performance of the device. In this work, we report the first practical implementation of these ideas in an organic light-emitting transistor. Highly emissive semiconductor single crystals were grown from a thiophene–phenylene co-oligomer 1,4-bis{5-[4-(trimethylsilyl)phenyl]thiophen-2-yl}benzene (TMS-PTPTP-TMS) with trimethylsilyl (TMS) terminal substituents, which promote the in-plane TDM orientation. Organic light-emitting transistors based on TMS-PTPTP-TMS showed ambipolar charge transport with efficient electroluminescence, and the single-crystal devices demonstrated linearly polarized electroluminescence with the polarization degree of 0.78 ± 0.06. The observed polarization properties of both electro- and photoluminescence are in full agreement with the solved crystal structure and the corresponding calculations. Our findings indicate that smart control of in-plane ordered TDMs via molecular packing is a promising approach to designing materials for highly efficient light-emitting electronic devices. This work (except the CV and TCTG OFET studies) was supported by the Russian Science Foundation (grant #18-12-00499) and was performed in the Enikolopov Institute of Synthetic Polymer Materials of Russian Academy of Sciences. The CV and TCTG OFET studies were supported by the Russian Science Foundation (project #20-73-10090). The steady-state PL studies were done by using the equipment purchased under the Lomonosov Moscow State University Program of Development. A. L. M. thanks the Erasmus+ Program for (partial) financial support of PL studies at Rijksuniversiteit Groningen in 2019. We acknowledge A. A. Mannanov for his participation at the initial stage of the project. We thank V. A. Postnikov for sharing his first growth experience of TMS-PTPTP-TMS crystals.This work (except the CV and TCTG OFET studies) was supported by the Russian Science Foundation (grant #18-12-00499) and was performed in the Enikolopov Institute of Synthetic Polymer Materials of Russian Academy of Sciences. The CV and TCTG OFET studies were supported by the Russian ScienceFoundation (project #20-73-10090). The steady-state PL studies were done by using the equipment purchased under the Lomonosov Moscow State University Program of Development. A. L. M. thanks the Erasmus+ Program for (partial) financial support of PL studies at Rijksuniversiteit Groningen in 2019. We acknowledge A. A. Mannanov for his participation at the initial stage of the project. We thank V. A. Postnikov for sharing his first growth experience of TMS-PTPTP-TMS crystals.