Diethynyl naphthalene derivatives with high ionization potentials for p-channel and n-channel organic field-effect transistors

We have developed and characterized diethynyl naphthalene derivatives with high ionization potentials, 2,6-bis [(naphthalen-2-yl) ethynyl]-naphthalene (BH-202) and 2,6-bis[(heptafluoronaphthalen-2-yl) ethynyl]-naphthalene (BF-202) for new organic semiconductors. Using x-ray diffraction, we have found that thin films of the two organic semiconductors have a high degree of molecular order. Organic field-effect transistors (OFETs) with BH-202 films showed p-type characteristics. By the optimization of the fabrication process, the device exhibited a high field-effect hole mobility up to 0.12 cm(2) V-1 s(-1) and a high on/off current ratio of 3.3 x 10(5). On the other hand, OFETs with BF-202 films showed n-type characteristics. The field-effect electron mobility was calculated to be 3.4 x 10(-3) cm(2) V-1 s(-1) and the on/off current ratio was 5.4 x 10(3).