Control of p- and n-type carriers by end-group substitution in oligo-p-phenylenevinylene-based organic field-effect transistors

摘要

Organic field-effect transistors (OFETs) consisting of vacuum-evaporated oligo-p-phenylenevinylene derivatives were prepared, and the device characteristics were evaluated. The fabricated OFETs showed typical p-type characteristics for methyl-substituted oligo-p-phenylenevinylene (OPV). A field-effect hole mdbility of 0.13 cm~2 V~(-1) s~(-1) emerged with a threshold voltage of -33 V and an on/off ratio of 5.8 X 10~5. On the other hand, OFETs showed typical n-type characteristics for trifluoromethyl-substituted OPV. A field-effect electron mobility of 0.013 cm~2 V~(-1) s~(-1) emerged with a threshold voltage of 45 V and an on/off ratio of 4.2 X 10~4. The authors have observed clear changes from p-channel to n-channel conductions in OFETs by chemically modifying oligo-p-phenylenevinylenes.