Enhancement Mode Flexible SnO2 Thin Film Transistors Via a UV/Ozone-Assisted Sol-Gel Approach

In this study, sol–gel-processed Li-doped SnO2-based thin-film transistors (TFTs) were fabricated on SiO2/p+ Si substrates. The influence of Li dopant (wt%) on the structural, chemical, optical, and electrical characteristics was investigated. By adding 0.5 wt% Li dopant, the oxygen vacancy formation process was successfully suppressed. Its smaller ionic size and strong bonding strength made it possible for Li to work as an oxygen vacancy suppressor. The fabricated TFTs consisting of 0.5 wt% Li-doped SnO2 semiconductor films delivered the field-effect mobility in a 2.0 cm2/Vs saturation regime and Ion/Ioff value of 1 × 108 and showed enhancement mode operation. The decreased oxygen vacancy inside SnO2 TFTs with 0.5 wt% Li dopant improved the negative bias stability of TFTs.

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Sol-Gel Processed Yttrium-Doped SnO2 Thin Film Transistors

Electronics ◽

10.3390/electronics9020254 ◽

2020 ◽

Vol 9 (2) ◽

pp. 254 ◽

Cited By ~ 2

Author(s):

Changmin Lee ◽

Won-Yong Lee ◽

Hyunjae Lee ◽

Seunghyun Ha ◽

Jin-Hyuk Bae ◽

...

Keyword(s):

Thin Film ◽

Oxygen Vacancy ◽

Electrical Transport ◽

Thin Film Transistors ◽

Vacancy Concentration ◽

Operation Mode ◽

Sol Gel ◽

Sno2 Thin Film ◽

Oxygen Vacancy Concentration ◽

Electrical Transport Properties

Y-doped SnO2 thin film transistors were successfully fabricated by means of sol-gel process. The effect of Y concentration on the structural, chemical, and electrical properties of sol-gel-processed SnO2 films was investigated via GIXRD, SPM, and XPS; the corresponding electrical transport properties of the film were also evaluated. The dopant, Y, can successfully control the free carrier concentration by suppressing the formation of oxygen vacancy inside SnO2 semiconductors due to its lower electronegativity and SEP. With an increase of Ywt%, it was observed that the crystallinity and oxygen vacancy concentration decreased, and the operation mode of SnO2 thin film transistor changed from accumulation (normally on) to enhancement mode (normally off) with a positive Vth shift.

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Effect of Annealing Ambient on SnO2 Thin Film Transistors Fabricated via An Ethanol-based Sol-gel Route

Electronics ◽

10.3390/electronics8090955 ◽

2019 ◽

Vol 8 (9) ◽

pp. 955 ◽

Cited By ~ 4

Author(s):

Hyunjae Lee ◽

Seunghyun Ha ◽

Jin-Hyuk Bae ◽

In-Man Kang ◽

Kwangeun Kim ◽

...

Keyword(s):

Thin Film ◽

Thin Film Transistors ◽

Field Effect ◽

High Performance ◽

Structural Characteristics ◽

Sol Gel ◽

Critical Role ◽

Sno2 Thin Film ◽

Field Effect Mobility ◽

Current Ratio

The effect of annealing ambient on SnO2 thin-film transistors (TFTs) fabricated via an ethanol-based sol-gel route was investigated. The annealing ambient has a significant effect on the structural characteristics and chemical composition and, in turn, the device performance. Although the crystalline-grain size of the SnO2 films annealed in air was the smallest, this size yielded the highest field-effect mobility. Compared with the minimization of boundary scattering via crystalline-size increase, augmentation of the free carrier concentration played a more critical role in the realization of high-performance devices. The fabricated SnO2 TFTs delivered a field-effect mobility, subthreshold swing, and on/off current ratio of 10.87 cm2/Vs, 0.87 V/decade, and 107, respectively.

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