The growth of solution-gelation TiO2 and its application to InAlAs/InGaAs metamorphic high-electron-mobility transistor

Photocurrent response loss of dye sensitized solar cells owing to top surface nanograss growth and bundling of anodic TiO2 nanotubes

“…Nanoscale materials are among the most interesting novel materials due to their exceptional physicochemical properties and large surface area [ 1 , 2 ]. Among various nanostructured materials, TiO 2 was an interesting material for functional and device applications owing to its unique electronic properties [ 3 ], very high specific surface area [ 4 ], high mechanical strength [ 5 ], and high electron mobility [ 6 , 7 ]. Among all the metal oxides, TiO 2 nanotubes (TNAs) as a wide-band gap nanostructured semiconductor is the most extensively studied candidate for optoelectronic and solar cell devices.…”

Surface-oxide-controlled InGaAs/InAlAs inverted-type metal-oxide-semiconductor high electron mobility transistors for sub-THz high-power amplifiers

“…To overcome this issue, metal-oxide-semiconductor (MOS) structures are indispensable. [10][11][12][13][14][15][16][17][18] Alternatively, Al 2 O 3 is an attractive oxide owing to its wide band gap (∼7.0 eV) and high dielectric constant (∼9.0). Furthermore, the thickness of Al 2 O 3 films must be optimized to suppress the gate leakage current and maximize transconductance (g m ) simultaneously.…”

Improved f T/f max in wide bias range by steam-annealed ultrathin-Al2O3 gate dielectrics for InP-based high-electron-mobility transistors

“…7) However, a large gate leakage current and a low breakdown voltage of InPbased HEMTs limit their operations. 8) Furthermore, wireless systems require transistors to have a high linearity because of the back-off in input power levels. To address these issues, insulated-gate structures with a low gate leakage current are desirable for radiofrequency (RF) operation over a wide bias range.…”

“…To address these issues, insulated-gate structures with a low gate leakage current are desirable for radiofrequency (RF) operation over a wide bias range. [8][9][10][11][12][13][14][15][16][17] Among the various types of dielectrics used to improve the performance of insulated-gate HEMTs, Al 2 O 3 has been one of the most attractive because of its wide band gap (∼7.0 eV), high dielectric constant (∼9.0), and high breakdown voltage (∼10 MV cm −1 ). Furthermore, considering the tradeoff between effective reduction in gate leakage current and degradation of transconductance (g m ), it is necessary to optimize the thickness of Al 2 O 3 .…”