High-performance ambipolar self-assembled Au/Ag nanowire based vertical quantum dot field effect transistor

Most lateral PbSe quantum dot field effect transistors (QD FETs) show a low on current/off current ( I _on/ I _off) ratio in charge transport measurements. A new strategy to provide generally better performance is to design PbSe QD FETs with vertical architecture, in which the structure parameters can be tuned flexibly. Here, we fabricated a novel room-temperature operated vertical quantum dot field effect transistor with a channel of 580 nm, where self-assembled Au/Ag nanowires served as source transparent electrodes and PbSe quantum dots as active channels. Through investigating the electrical characterization, the ambipolar device exhibited excellent characteristics with a high I _on/ I _off current ratio of about 1 × 10⁵ and a low sub-threshold slope (0.26 V/decade) in the p-type regime. The all-solution processing vertical architecture provides a convenient way for low cost, large-area integration of the device. (paper)