Solution-processed indium-free ZnO/SnO<sub>2</sub> bilayer heterostructures as a low-temperature route to high-performance metal oxide thin-film transistors with excellent stabilities

Nam, Sooji; Yang, Jong‐Heon; Cho, Sung Haeng; Choi, Ji Hun; Kwon, Oh‐Min; Park, Eun-Suk; Lee, Su‐Jae; Cho, Kyoung-Ik; Jang, Jaeyoung; Hwang, Chi‐Sun

doi:10.1039/c6tc03977d

Cited by 42 publications

(14 citation statements)

References 28 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…At the front channel of ITZO, Sn 4+ replaced In 3+ to provide additional electrons to increase electron concentration, forming a highly conductive channel and providing high mobility for devices. Moreover, a barrier height (0.15 eV) between IGZO and ITZO ( Figure 3b Nam et al prepared high-performance solution-processed indium-free ZnO/SnO2 TFTs at 300 °C by UV annealing [53]. The ZnO/SnO2 TFTs exhibited a mobility of 15.4 cm 2 /Vs, an outstanding on/off ratio of 10 8 , and superior bias stability.…”

Section: Electrical-property Modulationmentioning

confidence: 99%

“…Furthermore, due to the suppression of oxygen vacancy (Vo) defects in the bilayer film, the ZnO/SnO2 TFTs exhibited remarkable bias-stress stability (Figure 4b). Nam et al prepared high-performance solution-processed indium-free ZnO/SnO 2 TFTs at 300 • C by UV annealing [53]. The ZnO/SnO 2 TFTs exhibited a mobility of 15.4 cm 2 /Vs, an outstanding on/off ratio of 10 8 , and superior bias stability.…”

Section: Electrical-property Modulationmentioning

confidence: 99%

“…It should be mentioned that the transfer curve of the heterojunction TFTs shifted to the negative direction compared with the single-layer device, due to the formation of 2D electron gas. Nam et al prepared high-performance solution-processed indium-free ZnO/SnO2 TFTs at 300 °C by UV annealing [53]. The ZnO/SnO2 TFTs exhibited a mobility of 15.4 cm 2 /Vs, an outstanding on/off ratio of 10 8 , and superior bias stability.…”

Section: Mobility Enhancement By Forming 2d Electron Gasmentioning

confidence: 99%

See 2 more Smart Citations

Recent Advances of Solution-Processed Heterojunction Oxide Thin-Film Transistors

Zhao

Zhu

et al. 2020

Nanomaterials

View full text Add to dashboard Cite

Thin-film transistors (TFTs) made of metal oxide semiconductors are now increasingly used in flat-panel displays. Metal oxides are mainly fabricated via vacuum-based technologies, but solution approaches are of great interest due to the advantages of low-cost and high-throughput manufacturing. Unfortunately, solution-processed oxide TFTs suffer from relatively poor electrical performance, hindering further development. Recent studies suggest that this issue could be solved by introducing a novel heterojunction strategy. This article reviews the recent advances in solution-processed heterojunction oxide TFTs, with a specific focus on the latest developments over the past five years. Two of the most prominent advantages of heterostructure oxide TFTs are discussed, namely electrical-property modulation and mobility enhancement by forming 2D electron gas. It is expected that this review will manifest the strong potential of solution-based heterojunction oxide TFTs towards high performance and large-scale electronics.

show abstract

Section: Electrical-property Modulationmentioning

confidence: 99%

Section: Electrical-property Modulationmentioning

confidence: 99%

Section: Mobility Enhancement By Forming 2d Electron Gasmentioning

confidence: 99%

See 1 more Smart Citation

Recent Advances of Solution-Processed Heterojunction Oxide Thin-Film Transistors

Zhao

Zhu

et al. 2020

Nanomaterials

View full text Add to dashboard Cite

show abstract

“…To enhance charge transport in MO semiconductor, several methods have been exploited including the use of low dimensional heterostructures, metallic nanocomposition implanted in the channel layer, adoption of high‐ k insulators, and in situ metallic oxide capping . Among them, semiconducting heterostructures including bi‐ or multilayers of different materials have drawn attention because of the high carrier mobility and large driving current of the resulting TFTs and possibility to investigate new physical/transport mechanisms . The enhanced carrier mobility and on‐current in these heterostructures originate from the large difference in the Fermi energy levels of semiconducting layers .…”

Section: Electrical Properties Of the Indicated Mo Tfts (The Values Amentioning

confidence: 99%

Corrugated Heterojunction Metal‐Oxide Thin‐Film Transistors with High Electron Mobility via Vertical Interface Manipulation

Lee

Kim

et al. 2018

Advanced Materials

View full text Add to dashboard Cite

A new strategy is reported to achieve high-mobility, low-off-current, and operationally stable solution-processable metal-oxide thin-film transistors (TFTs) using a corrugated heterojunction channel structure. The corrugated heterojunction channel, having alternating thin-indium-tin-zinc-oxide (ITZO)/indium-gallium-zinc-oxide (IGZO) and thick-ITZO/IGZO film regions, enables the accumulated electron concentration to be tuned in the TFT off- and on-states via charge modulation at the vertical regions of the heterojunction. The ITZO/IGZO TFTs with optimized corrugated structure exhibit a maximum field-effect mobility >50 cm V s with an on/off current ratio of >10 and good operational stability (threshold voltage shift <1 V for a positive-gate-bias stress of 10 ks, without passivation). To exploit the underlying conduction mechanism of the corrugated heterojunction TFTs, a physical model is implemented by using a variety of chemical, structural, and electrical characterization tools and Technology Computer-Aided Design simulations. The physical model reveals that efficient charge manipulation is possible via the corrugated structure, by inducing an extremely high carrier concentration at the nanoscale vertical channel regions, enabling low off-currents and high on-currents depending on the applied gate bias.

show abstract

“…A notably successful strategy to enhance TFT performance, including MO‐ and organic‐based TFTs, utilizes semiconducting channel heterojunctions . Here, the Fermi energy alignment between two semiconductors in contact leads to band bending at the semiconductor heterojunction, thereby forming a two‐dimensional electron gas (2DEG) at this interface . To date, 2DEG MO transistors have been fabricated using pristine/metal‐doped In 2 O 3 and ZnO heterojunctions, with ZnO/ZnMgO and In 2 O 3 /ZnO being the most investigated .…”

Section: Performance Metrics Of the Indicated Tft Devices On Si/sio2 mentioning

confidence: 99%

Polymer Doping Enables a Two‐Dimensional Electron Gas for High‐Performance Homojunction Oxide Thin‐Film Transistors

et al. 2018

View full text Add to dashboard Cite

deposition (PLD), and radiofrequency sputtering. [2,[11][12][13] Nevertheless, solutionprocessing of MO precursors holds significant promise for lower cost production and compatibility with flexible substrates. [2,9,14,15] In this regard, indium oxide (In 2 O 3 ) is one of the most investigated solution-processed oxide semiconductors, [7,[16][17][18][19][20][21] however, the carrier density of pristine In 2 O 3 is difficult to control and In 2 O 3 films are usually polycrystalline, limiting their performance uniformity over large areas as well as mechanical flexibility. [22] To address both of these issues, metals such as Zn and/or Ga are added to In 2 O 3 , enabling the growth of amorphous MO thin films with enhanced electronic properties and ultimately affording far more stable TFT characteristics. [22][23][24][25][26] Recently, we reported a new strategy for high performance, near-zero threshold voltage (V Th ), bias stress-stable, and amorphous In 2 O 3 films and TFTs by simply doping the In 2 O 3 with an electrically insulating polymer such as poly(4-vinylphenol) (PVP) or polyethylenimine (PEI) to afford amorphous MO:polymer blend semiconducting nanocomposites. [2,17,22] The attraction of electron-rich PEI versus PVP is that the TFT High-performance solution-processed metal oxide (MO) thin-film transistors (TFTs) are realized by fabricating a homojunction of indium oxide (In 2 O 3 ) and polyethylenimine (PEI)-doped In 2 O 3 (In 2 O 3 :x% PEI, x = 0.5-4.0 wt%) as the channel layer. A two-dimensional electron gas (2DEG) is thereby achieved by creating a band offset between the In 2 O 3 and PEI-In 2 O 3 via work function tuning of the In 2 O 3 :x% PEI, from 4.00 to 3.62 eV as the PEI content is increased from 0.0 (pristine In 2 O 3 ) to 4.0 wt%, respectively. The resulting devices achieve electron mobilities greater than 10 cm 2 V −1 s −1 on a 300 nm SiO 2 gate dielectric. Importantly, these metrics exceed those of the devices composed of the pristine In 2 O 3 materials, which achieve a maximum mobility of ≈4 cm 2 V −1 s −1 . Furthermore, a mobility as high as 30 cm 2 V −1 s −1 is achieved on a high-k ZrO 2 dielectric in the homojunction devices. This is the first demonstration of 2DEG-based homojunction oxide TFTs via band offset achieved by simple polymer doping of the same MO material. Thin-Film TransistorsThe ORCID identification number(s) for the author(s) of this article can be found under https://doi.As a consequence of their outstanding charge transport properties and excellent optical transparency, metal oxide thin-film transistors (MOTFTs) have been heavily investigated for applications in state-of-the-art flat panel display technologies and next-generation electronics. [1][2][3][4][5][6][7][8][9][10] To date, several growth techniques have been utilized to fabricate MO films for TFTs including atomic layer deposition (ALD), pulsed-laser

show abstract

Solution-processed indium-free ZnO/SnO₂ bilayer heterostructures as a low-temperature route to high-performance metal oxide thin-film transistors with excellent stabilities

Abstract: The ZnO/SnO2 bilayer TFTs exhibited outstanding electron mobilities and excellent electrical stabilities against a variety of bias stresses.

Cited by 42 publications

References 28 publications

Recent Advances of Solution-Processed Heterojunction Oxide Thin-Film Transistors

Recent Advances of Solution-Processed Heterojunction Oxide Thin-Film Transistors

Corrugated Heterojunction Metal‐Oxide Thin‐Film Transistors with High Electron Mobility via Vertical Interface Manipulation

Polymer Doping Enables a Two‐Dimensional Electron Gas for High‐Performance Homojunction Oxide Thin‐Film Transistors

Contact Info

Product

Resources

About

Solution-processed indium-free ZnO/SnO2 bilayer heterostructures as a low-temperature route to high-performance metal oxide thin-film transistors with excellent stabilities

Abstract: The ZnO/SnO2 bilayer TFTs exhibited outstanding electron mobilities and excellent electrical stabilities against a variety of bias stresses.

Cited by 42 publications

References 28 publications

Recent Advances of Solution-Processed Heterojunction Oxide Thin-Film Transistors

Recent Advances of Solution-Processed Heterojunction Oxide Thin-Film Transistors

Corrugated Heterojunction Metal‐Oxide Thin‐Film Transistors with High Electron Mobility via Vertical Interface Manipulation

Polymer Doping Enables a Two‐Dimensional Electron Gas for High‐Performance Homojunction Oxide Thin‐Film Transistors

Contact Info

Product

Resources

About

Solution-processed indium-free ZnO/SnO₂ bilayer heterostructures as a low-temperature route to high-performance metal oxide thin-film transistors with excellent stabilities