Diacenopentalene dicarboximides as new n-type organic semiconductors for field-effect transistors

摘要

N,N'-Dihexyl-dibenzopentalene dicarboximide (DBPDI) and N,N'-dioctyl-dinaphthopentalene dicarboximide (DNPDI) were successfully synthesized as new n-type semiconducting materials. They have good solubility in common organic solvents. DBPDI and DNPDI are thermally stable, with decomposition temperatures at 419 and 460 degrees C, respectively, based on thermogravimetric analysis, and melt at 354 and 387 degrees C as measured by differential scanning calorimetry. Their optical and electrochemical properties were studied by UV-vis absorption and cyclic voltammetry measurements. Time-dependent density functional theory calculations (TDDFT) were used to explain their unique electronic absorption spectra. DBPDI and DNPDI have relatively low-lying LUMO energy levels at -3.76 eV and -3.45 eV and HOMO energy levels at -5.84 eV and -5.72 eV, respectively. Their application in organic field-effect transistors (FETs) was investigated. Both DBPDI and DNPDI showed n-type field-effect transistor behavior. The DBPDI device obtained by solution-processing technique displayed an average electron mobility of up to 0.06 cm(2) V-1 s(-1) with an I-on/I-off ratio of 2.9 x 10(6).