Directional Crystallization from the Melt of an Organic p-Type and n-Type Semiconductor Blend

Directional crystallization from the melt has been used as a tool to grow parallel crystalline stripes of p- and n-type molecular semiconductors. To start, phase behavior 2,7-dioctyl[1]benzothieno[3,2-b][1]benzothiophene (C8-BTBT-C8): tetracyanoquinodimethane (TCNQ) blends (molar ratio 20:1 1:1) investigated by variable-temperature X-ray diffraction, differential scanning calorimetry, polarized optical microscopy. The partial charge transfer between C8-BTBT-C8 donor TCNQ acceptor function temperature studied. Blends 10:1 have selected for directional because they show similar thermotropic comparable that pure C8-BTBT-C8. results suggest moderate cooling rates (6 12 °C min–1) leads digitated growth mode gives rise C8-BTBT-C8-TCNQ charge-transfer complexes (C8-BTBT-C8-TCNQ CT), confirmed confocal Raman imaging. diffraction reveals high preferential orientation good in-plane alignment both CT crystallites.