Anisotropic field effect mobility in single crystal pentacene

Fan-shaped electrodes were designed on $\mathrm{Si}∕\mathrm{Si}{\mathrm{O}}_2$ substrate to measure the anisotropic field effect mobility in freestanding single crystal pentacene. Field effect transistor was fabricated by placing single crystal pentacene on the prepatterned electrodes. The contact between the electrodes and single crystal pentacene was enhanced by applying pressure. Angle dependence of field effect mobility in single crystal pentacene showed remarkably anisotropic behavior. The highest mobility value was estimated to be $\sim 2.3{\mathrm{cm}}^2∕\mathrm{V}\mathrm{s}$ at room temperature.