Temperature dependence of carrier mobility in hydrogenated germanane field-effect transistor with various electrode materials

Abstract

Germanane, a layered material in which single-layer germanium is terminated by hydrogen atoms, was utilized as a channel material in back-gate-type FETs. Titanium, aluminum, and nickel were used as source and drain electrodes of FETs, and most of the fabricated FETs showed ambipolar characteristics. Among the three electrode materials, nickel was the best for high field-effect carrier mobility. It was also found that the mobility changes with temperature T according to the T −3/2 law below 273 K, whereas the mobility change deviates from the law of T −3/2 above 293 K.