Drift velocity saturation in field-effect transistors based on single CdSe nanowires

Area of Science:

• Materials Science
• Condensed Matter Physics
• Nanotechnology

Background:

• Semiconductor nanowire (NW) field-effect transistors (FETs) are crucial for nanoelectronic and optoelectronic devices.
• Understanding high electric field transport is vital for device physics and applications.
• Drift velocity saturation phenomena are rarely reported in NW FETs.

Purpose of the Study:

• Investigate high electric field transport characteristics in Cadmium Selenide (CdSe) NW FETs.
• Observe and analyze current saturation due to drift velocity saturation.
• Determine key transport parameters like low-field mobility and saturation drift velocity.

Main Methods:

• Fabrication and characterization of CdSe NW FETs.
• Measurement of output characteristic curves under varying electric fields.
• Analysis of current saturation to extract transport properties.

Main Results:

• Observed current saturation phenomenon at high electric fields in CdSe NW FETs.
• Obtained low electric field mobility values ranging from 265.2 to 388.0 cm² V⁻¹ s⁻¹.
• Measured saturation drift velocity between 5.1 × 10⁵ and 7.0 × 10⁵ cm s⁻¹, decreasing with charge density, indicating electron-phonon scattering dominance.

Conclusions:

• This work presents the first experimental report of saturation drift velocity in CdSe NW FETs.
• The findings highlight the significance of electron-phonon scattering at high electric fields.
• Results offer valuable guidance for designing advanced CdSe NW-based nanoelectronic and optoelectronic devices.