Room-temperature transient carrier transport in germanium single-hole/electron transistors

We report the experimental observation of transient carrier transports at room temperature in a Ge quantum-dot (QD) single-hole transistor (SHT) and single-electron transistor (SET). In addition to room-temperature Coulomb oscillations, hysteresis effects have been observed in the steady-state tunneling current of a Ge-SHT and a Ge-SET as gate voltage is swept in a loop. Time-dependent tunneling current of a Ge-SHT and a Ge-SET displays clear oscillatory or staircase behavior at a constant voltage stress condition, which indicates transient charging/discharging of electrons and holes via a Ge QD due to substantial quantum mechanics effect.