Nanocrystal-mediated charge screening effects in nanowire field-effect transistors

Abstract

Effect of gate bias sweep rate on the electronic properties of ZnO nanowire field-effect transistors under different environments Appl.ZnO nanowire field-effect transistors having an omega-shaped floating gate ͑OSFG͒ have been successfully fabricated by directly coating CdTe nanocrystals ͑ϳ6 Ϯ 2.5 nm͒ at room temperature, and compared to simultaneously prepared control devices without nanocrystals. Herein, we demonstrate that channel punchthrough may occur when the depletion from the OSFG takes place due to the trapped charges in the nanocrystals. Electrical measurements on the OSFG nanowire devices showed static-induction transistorlike behavior in the drain output I DS -V DS characteristics and a hysteresis window as large as ϳ3.1 V in the gate transfer I DS -V GS characteristics. This behavior is ascribed to the presence of the CdTe nanocrystals, and is indicative of the trapping and emission of electrons in the nanocrystals. The numerical simulations clearly show qualitatively the same characteristics as the experimental data and confirm the effect, showing that the change in the potential distribution across the channel, induced by both the wrapping-around gate and the drain, affects the transport characteristics of the device. The cross-sectional energy band and potential profile of the OSFG channel corresponding to the "programed ͑noncharged͒" and "erased ͑charged͒" operations for the device are also discussed on the basis of the numerical capacitance-voltage simulations.

Floating-gated memory based on carbon nanotube field-effect transistors with Si floating dots

“…In recent years, nonvolatile memories with nanowires as channels or with floating dots as charge storage nodes have been developed. [35][36][37][38][39] The hysteresis widths of these nonvolatile memories are plotted in Fig. 6.…”

“…In Ref. 37, the channel consists of a ZnO nanowire with CdTe nanocrystals. The diameter of the nanowire is in the range of 90-120 nm.…”

High-Performance Nanofloating Gate Memory Based on Lead Halide Perovskite Nanocrystals

“…During the high-temperature deposition process, metal atoms may penetrate into the tunneling layer, thus resulting in a large leakage current . Alternatively, the solution-processable semiconducting NCs have emerged as promising charge trapping media in NFGMs. , In this case, the charges are stored in the conduction or valence band of semiconducting NCs. , Nevertheless, the misalignment of energy levels between semiconducting NCs and channel semiconductor will induce a large energy barrier for charge tunneling, which restricts the charge storage capabilities of semiconductor NCs.…”