Gate-tunable selective operation of single electron/hole transistor modes in a silicon single quantum dot at room temperature

We demonstrate a gate-tunable selective operation of single-electron- transistor (SET) and single-hole-transistor (SHT) in a unit silicon (Si) quantum dot (QD) system at room temperature. The small sized Si-QD (∼7 nm) with well-defined tunnel barriers, which are formed along the p⁺-i-n ⁺ Si nanowire in both the conduction band and the valence band, permits the alternative use of quantum states for electrons or holes to be selected by the polarity of the gate bias. The device shows clear Coulomb blockade and negative differential-conductance oscillations on both gate-tunable SET and SHT modes as a result of quantum transport in the p⁺-i- n⁺ Si QD system.