ИСТИНА

Organic light-emitting transistors (OLET) are one o f the most promising devices with a potential to outperform the organic-light emitting diodes i . In OLETs, the current flows through an ultrathin light-emitting layer in contac t with the gate dielectric. This geometry motivates fabrication of highly-luminescent monolay er semiconducting films using various self-assembly techniques. Amongst them, the Langmui r-Blodgett (LB) technique is one of the most robust and fastest for producing the monolayer s with the well-controlled structure ii . Thiophene-phenylene co-oligomers (TPCO) in crystals have been shown to combine high yield of photoluminescence (PL) and efficient charg e transport iii . Therefore, functionalized TPCO is a promising material for a highly luminesce nt semiconducting monolayer. Here we report PL properties of LB films prepared f rom novel organosilicon derivative of TPCO, O(Si-Und-PTTP-TMS) 2 (Fig.1a). We observed strong PL from the LB films (Fig.1b,c) with the PL spectrum red-shifted as comp ared to solution (Fig.1d), and similar to the one observed previously from TPCO crystals, TMS -PTTP-TMS iv . The time-resolved PL exhibits two characteristic decays at ~30 ps and ~2 50 ps (Fig.1e). The latter timescale is assigned to the radiative lifetime as it is similar to the one observed in diluted solution (~300 ps), while the former is attributed to PL quenching due to molecule packing in the LB film. Nonetheless, tight molecular packing does not compl etely quench PL as often observed for conjugated molecules as e.g. oligothiophenes. We wi ll furhter discuss the relation between the structrue of monolayer O(Si-Und-PTTP-TMS) 2 films and their PL properties.