Eliminating gate bias stress effects in organic field-effect transistors

We report on organic field-effect transistors with unprecedented resistance against gate bias stress. The single crystal and thin-film transistors combine small molecule organic semiconductors and an organic gate dielectric with a remarkable electrical breakdown strength. The single crystal devices have no current hysteresis. Extended gate bias stress leads to almost unmeasurable changes in the transfer characteristics: the induced interface state density is of order 10$^{9}$/cm$^{2}$. In contrast, stress-induced trap densities of order 10$^{12}$/cm$^{2 }$ have been identified previously in devices with SiO$_{2}$ or OTS-treated SiO$_{2}$ gate dielectrics. Therefore, adverse gate bias stress effects are not generic to oligocene organic semiconductors, and there is no conceptual limitation for the stability of organic-based transistors in contrast to hydrogenated amorphous silicon.