Аннотация:Organic semiconducting crystals cancombine efficient charge transport and high luminescence1allowingfabrication ofhigh-performance organic optoelectronic devices such as light-emitting transistors and lasers. One of the promising approach to enhancethe luminescence properties of organic semiconducting crystals is doping by highly luminescent molecules.2If the absorption spectrum of the dopant overlaps with the fluorescence spectrum of the host material,the host-dopant energy transfer can improve the luminescent properties of the material. Earlier the dopant-enhanced luminescencewas demonstrated for avapor-grownorganic semiconducting crystals,2whereas doping of solution-processed crystals is more advantageousfor organic electronics printing technologies.In this work,we demonstrate thatthe photoluminescent(PL)properties of organic semiconductingsingle crystals areenhanced by controlled doping via solution processing. As the host material we used thiophene-phenylene co-oligomer (TPCO)5,5'-bis(4-(trimethylsilyl)phenyl)-2,2'-bithiophene (TMS-PTTP-TMS)as it demonstrated a promising combination of high PL andefficient charge transport. We observedthatthePL spectrashift to the redupon increasing the dopant concentration(Fig.1b). Time-resolved PL data(Fig.1c)show that the red part of PL is delayedand decayslonger as compared to the blue part. These PL dynamic features indicate efficient host-dopant energy transfer (Fig.1d), with the dopant molar concentration0.7% providing the maximum value of PL quantum external yield(QY)(inset in Fig.1a).We conclude that doping of organic semiconducting single crystalsby a highly luminescent dopantvia solution processing is apromising routefor designingthenovel organic optoelectronic materialscompatible with printing technologiesof devices.