Min Jung Lee

Mobility enhancement in amorphous InGaZnO thin-film transistors by Ar plasma treatment

The effects of Ar plasma treatment on the back-channel of amorphous InGaZnO (a-IGZO) thin-film transistors are investigated. A decrease in metallic ion-oxygen bonding in the Ar plasma-treated a-IGZO channel layer was observed by X-ray photoelectron spectroscopy (XPS) depth profile analysis. An increase in the channel charge carrier concentration is estimated from the increased oxygen vacancy atomic ratio using XPS curve decomposition analysis. The plasma-treated area of the a-IGZO back-channel is varied with a photoresist screening layer with a varied open window length (Lp). From the Lp-dependent channel resistance analysis, a carrier concentration-dependent field-effect mobility enhancement is observed.The effects of Ar plasma treatment on the back-channel of amorphous InGaZnO (a-IGZO) thin-film transistors are investigated. A decrease in metallic ion-oxygen bonding in the Ar plasma-treated a-IGZO channel layer was observed by X-ray photoelectron spectroscopy (XPS) depth profile analysis. An increase in the channel charge carrier concentration is estimated from the increased oxygen vacancy atomic ratio using XPS curve decomposition analysis. The plasma-treated area of the a-IGZO back-channel is varied with a photoresist screening layer with a varied open window length (Lp). From the Lp-dependent channel resistance analysis, a carrier concentration-dependent field-effect mobility enhancement is observed.

Binder‐Free and Full Electrical‐Addressing Free‐Standing Nanosheets with Carbon Nanotube Fabrics for Electrochemical Applications

Inorganic functional nanosheets (NSs), which are unilamellar nanoscale building blocks having a thickness on the order of nanometers with lateral dimensions of sub-micrometers, are characterized by their ultra-large surface area per volume, stoichiometrically well-defi ned chemical composition, single crystalline structure with high crystallinity, and unique physicochemical properties. [ 1 , 2 ] Therefore, they have been considered excellent nanomaterials that provide superior performance in various applications such as catalysts, [ 3 ] sensors, [ 4 ] die-sensitized solar cells, [ 5 , 6 ] super-capacitors, [ 7 ] batteries [ 8 ] and fuel cells. [ 9 ]

Modulation of the operational characteristics of amorphous In–Ga–Zn–O thin-film transistors by In2O3 nanoparticles

The structure of thin-film transistors (TFTs) based on amorphous In–Ga–Zn–O (a-IGZO) was modified by spin coating a suspension of In2O3 nanoparticles on a SiO2/p++ Si layered wafer surface prior to the deposition of IGZO layer by room-temperature sputtering. The number of particles per unit area (surface density) of the In2O3 nanoparticles could be controlled by applying multiple spin coatings of the nanoparticle suspension. During the deposition of IGZO, the In2O3 nanoparticles initially located on the substrate surface migrated to the top of the IGZO layer indicating that they were not embedded within the IGZO layer, but they supplied In to the IGZO layer to increase the In concentration in the channel layer. As a result, the channel characteristics of the a-IGZO TFT were modulated so that the device showed an enhanced performance as compared with the reference device prepared without the nanoparticle treatment. Such an improved device performance is attributed to the nano-scale changes in the structure of (InO)n ordering assisted by increased In concentration in the amorphous channel layer.