Bandgap-Engineered in Indium–Gallium–Oxide Ultraviolet Phototransistors

Electrolyte–insulator–semiconductor (EIS) sensors, used in applications such as pH sensing and sodium ion sensing, are the most basic type of ion-sensitive field-effect transistor (ISFET) membranes. Currently, some of the most popular techniques for synthesizing such sensors are chemical vapor deposition, reactive sputtering and sol-gel deposition. However, there are certain limitations on such techniques, such as reliability concerns and isolation problems. In this research, a novel design of an EIS membrane consisting of an optical material of indium gallium oxide (IGO) was demonstrated. Compared with conventional treatment such as annealing, Ti doping and CF4 plasma treatment were incorporated in the fabrication of the film. Because of the effective treatment of doping and plasma treatment, the defects were mitigated and the membrane capacitance was boosted. Therefore, the pH sensitivity can be increased up to 60.8 mV/pH. In addition, the hysteresis voltage can be improved down to 2.1 mV, and the drift voltage can be suppressed to as low as 0.23 mV/h. IGO-based membranes are promising for future high-sensitivity and -stability devices integrated with optical applications.

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Thin-film transistors with amorphous indium gallium oxide channel layers

Journal of Vacuum Science & Technology B Microelectronics and Nanometer Structures Processing Measurement and Phenomena ◽

10.1116/1.2366569 ◽

2006 ◽

Vol 24 (6) ◽

pp. 2702 ◽

Cited By ~ 59

Author(s):

H. Q. Chiang ◽

D. Hong ◽

C. M. Hung ◽

R. E. Presley ◽

John F. Wager ◽

...

Keyword(s):

Thin Film ◽

Thin Film Transistors ◽

Gallium Oxide ◽

Indium Gallium

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AC/DC Rectification With Indium Gallium Oxide Thin-Film Transistors

IEEE Electron Device Letters ◽

10.1109/led.2010.2042424 ◽

2010 ◽

Vol 31 (4) ◽

pp. 314-316 ◽

Cited By ~ 7

Author(s):

B.R. McFarlane ◽

P. Kurahashi ◽

D.P. Heineck ◽

R.E. Presley ◽

E. Sundholm ◽

...

Keyword(s):

Thin Film ◽

Thin Film Transistors ◽

Gallium Oxide ◽

Oxide Thin Film ◽

Indium Gallium

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Transparent ring oscillator based on indium gallium oxide thin-film transistors

Solid-State Electronics ◽

10.1016/j.sse.2006.02.004 ◽

2006 ◽

Vol 50 (3) ◽

pp. 500-503 ◽

Cited By ~ 123

Author(s):

R.E. Presley ◽

D. Hong ◽

H.Q. Chiang ◽

C.M. Hung ◽

R.L. Hoffman ◽

...

Keyword(s):

Thin Film ◽

Thin Film Transistors ◽

Gallium Oxide ◽

Ring Oscillator ◽

Oxide Thin Film ◽

Indium Gallium

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Experimental and theoretical evidence for hydrogen doping in polymer solution-processed indium gallium oxide

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.2007897117 ◽

2020 ◽

Vol 117 (31) ◽

pp. 18231-18239

Author(s):

Wei Huang ◽

Po-Hsiu Chien ◽

Kyle McMillen ◽

Sawankumar Patel ◽

Joshua Tedesco ◽

...

Keyword(s):

Fourier Transform ◽

Metal Oxide ◽

Electron Mobility ◽

Gallium Oxide ◽

Double Resonance ◽

Oxide Semiconductor ◽

Ab Initio Molecular Dynamics ◽

Solution Processed ◽

X Ray ◽

Indium Gallium

The field-effect electron mobility of aqueous solution-processed indium gallium oxide (IGO) thin-film transistors (TFTs) is significantly enhanced by polyvinyl alcohol (PVA) addition to the precursor solution, a >70-fold increase to 7.9 cm2/Vs. To understand the origin of this remarkable phenomenon, microstructure, electronic structure, and charge transport of IGO:PVA film are investigated by a battery of experimental and theoretical techniques, including In K-edge and Ga K-edge extended X-ray absorption fine structure (EXAFS); resonant soft X-ray scattering (R-SoXS); ultraviolet photoelectron spectroscopy (UPS); Fourier transform-infrared (FT-IR) spectroscopy; time-of-flight secondary-ion mass spectrometry (ToF-SIMS); composition-/processing-dependent TFT properties; high-resolution solid-state1H,71Ga, and115In NMR spectroscopy; and discrete Fourier transform (DFT) analysis with ab initio molecular dynamics (MD) liquid-quench simulations. The71Ga{1H} rotational-echo double-resonance (REDOR) NMR and other data indicate that PVA achieves optimal H doping with a Ga···H distance of ∼3.4 Å and conversion from six- to four-coordinate Ga, which together suppress deep trap defect localization. This reduces metal-oxide polyhedral distortion, thereby increasing the electron mobility. Hydroxyl polymer doping thus offers a pathway for efficient H doping in green solvent-processed metal oxide films and the promise of high-performance, ultra-stable metal oxide semiconductor electronics with simple binary compositions.

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