Thin film transistors by solution-based indium gallium zinc oxide/carbon nanotubes blend

Fabrication of Indium Gallium Zinc Oxide (IGZO) TFTs Using a Solution-Based Process

“…These values were similar to the values that were previously reported for IGZO transistors that were deposited using solution-based processes [15][16][17][18]25].…”

“…Until recently, IGZO thin films were formed using pulsed laser deposition (PLD) [1,[10][11][12], RF magnetron sputtering [2,13,14], direct current (DC) magnetron sputtering [3], inkjet printing [15] and spin coating [16][17][18]. The PLD, RF sputtering, and DC sputtering methods are all based on the vapor deposition process.…”

Band offsets in HfO2/InGaZnO4 heterojunctions

“…Assuming parabolic density of states within the a-IGZO, we determined an optical energy gap of $3.2 eV from Tauc plots, 15 similar to previous reports. [16][17][18][19][20][21] To obtain the band offsets from XPS measurements, three samples were characterized: a 2000 Å thick IGZO layers grown on Si, 300 Å HfO 2 /IGZO, and 35 Å HfO 2 /IGZO.…”

Chemically Functionalized, Well‐Dispersed Carbon Nanotubes in Lithium‐Doped Zinc Oxide for Low‐Cost, High‐Performance Thin‐Film Transistors

“…[ 23 ] In parallel, single-walled carbon nanotubes (SWNTs) have been recently regarded as another mobility enhancer that can be incorporated into metal oxide semiconductors owing to their outstanding electronic properties with high carrier mobility and ballistic conduction pathways provided by the nanotubes. [24][25][26] Liao and co-workers demonstrated the fabrication of IZO/SWNT TFTs with a fi eld-effect mobility of 140 cm 2 V −1 s −1 and an on/off current ratio of ≈10 7 . [ However, to date, indium-free TFTs employing SWNT-doped ZnO channel layers have remained unexplored.…”

“…This increased mobility can be explained that the SWNTs provide fast transport pathways of electrons under a static bias condition and form a subpercolated network in the fi lm, which causes the reduction of the effective channel length. [ 24,25,32 ] Above the SWNT composition of 0.01 wt%, the opposite trends in both mobility and threshold voltage appeared, indicating the adverse impact of excessive carbons over the optimal composition achieving the uniform distribution in ultrathin oxide semiconductors. Note that the thickness of an oxide semiconductor as a channel layer for TFTs is typically around a few tens of nanometers and the length of SWNTs is around 500 nm; [ 38 ] thus, the critical concentration for spatially separating CNTs in an ultrathin 2D layer can play a crucial role in determining the electrical properties of SWNT-incorporated oxide layers.…”