Solution-processed naphthalene diimide derivatives as n-type semiconductor materials

Two soluble 1,4,5,8-naphthalenetetracarboxylic diimide (NTCDI) derivatives with phenylmethyl and (trifluoromethyl)benzyl groups (NTCDI-P and NTCDI-F, respectively) were synthesized and used as semiconductor layers in organic thin-film transistors (OTFTs) by a spin-coating process in air. These two synthesized materials were characterized by H-1 NMR and UV-vis spectra as well as mass analysis. The morphology and crystallinity of spin-coated NTCDI-P and NTCDI-F films have been inspected using atomic force microscopy (AFM) and X-ray diffraction (XRD), respectively. The channel mobilities of these two NTCDI derivatives were calculated to be about 1.2 x 10(-1) cm(2) V-1 s(-1) in air, which degraded slightly while stabilized for NTCDI-F OTFTs after exposure in air for 1 month.