Low Operating Voltage Single ZnO Nanowire Field-Effect Transistors Enabled by Self-Assembled Organic Gate Nanodielectrics

Abstract

The development of nanowire transistors enabled by appropriate dielectrics is of great interest for flexible electronic and display applications. In this study, nanowire field-effect transistors (NW-FETs) composed of individual ZnO nanowires are fabricated using a self-assembled superlattice (SAS) as the gate insulator. The 15-nm SAS film used in this study consists of four interlinked layer-by-layer self-assembled organic monolayers and exhibits excellent insulating properties with a large specific capacitance, 180 nF/cm2, and a low leakage current density, 1 x 10(-8) A/cm2. SAS-based ZnO NW-FETs display excellent drain current saturation at Vds = 0.5 V, a threshold voltage (Vth) of -0.4 V, a channel mobility of approximately 196 cm2/V s, an on-off current ratio of approximately 10(4), and a subthreshold slope of 400 mV/dec. For comparison, ZnO NW-FETs are also fabricated using 70-nm SiO2 as the gate insulator. Implementation of the SAS gate dielectric reduces the NW-FET operating voltage dramatically with more than 1 order of magnitude enhancement of the on-current. These results strongly indicate that SAS-based ZnO NW-FETs are promising candidates for future flexible display and logic technologies.

Fabrication of fully transparent nanowire transistors for transparent and flexible electronics

“…3b,d. These devices exhibit typical enhancement mode long-channel FET [35][36][37][38][39][40] . Because the extraction procedure for m eff involves uncertainties due to the required capacitance estimation (see Methods), NWTs can be compared with planar transistors by comparing the I on and g m per unit width (g m /W), using the nanowire diameter as the device width.…”

Spectroscopic and Theoretical Study of the Grafting Modes of Phosphonic Acids on ZnO Nanorods

“…13 Therefore, the present decade has seen a surge of interest in the modification of metal oxides (TiO 2 , AgO, Al 2 O 3 , ZrO, ZnO, ITO) with SAM having various anchoring groups, among which phosphonic moieties were proven to be an efficient alternative to the more often adopted carboxylic and siloxane tethering functionalities. 14−17 Among mentioned metal oxides, nanostructured ZnO, a wide-band-gap semiconductor (E g = 3.37 eV at room temperature) 18 used in sensors, 19 electronic devices, 20,21 and solar cells, 22−24 is a promising substrate for the design of SAM-based organic− inorganic materials of technological relevance. 25−32 Examples of SAM-functionalized ZnO nanostructures include nanorods modified either with carboxyalkylphosphonic acids (HOOC-(CH 2 ) n P(O)(OH) 2 (n = 2, 9)) for biosensing 25 or with C60-functionalized phosphonic linkers for photonic devices 26 and nanowire-based ZnO field-effect transistors (FET) which use long-chain alkylphosphonic acids as gate dielectrics.…”

1∕f noise of SnO2 nanowire transistors

“…Details of this self-assembly procedure SAND have been reported previously. 10,11 The SnO 2 nanowries were synthesized on a SiO 2 / Si substrate covered with 10 nm gold nanoparticles, using a process performed in Ar with a trace of oxygen and employing laser ablation from a Sn target ͑99.99%, AlfaAesar͒. Details of the synthesis procedure have been described previously.…”