Free-standing tetracene single crystal field effect transistor

We have fabricated and studied field effect transistors (FETs) on the optically transparent free-standing organic single crystals of tetracene. These FETs exhibit effective hole channel mobility μeff up to 0.15 cm2/Vs and on–off ratios up to 2×107. Using measured values of μeff, thermal activation energy, and a simple model, we deduce an intrinsic free carrier mobility in the range of tens of cm2/Vs, similar to that found in pentacene crystals. These values should be considered only as a rough indication of achievable mobilities in samples much purer than those presently studied. The obtained results show the possibility of FET behavior in transparent crystals with low intrinsic carrier density.