A General Route to Printable High‐Mobility Transparent Amorphous Oxide Semiconductors

Lee, Doo-Hyoung; Chang, Yu-Jen; Herman, Gregory S.; Chang, Chih-Hung

doi:10.1002/adma.200600961

Cited by 404 publications

(323 citation statements)

References 13 publications

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“…An aqueous route allows for the preparation of IZO TFTs at a lower temperature compared with that used in the previously reported 2-methoxyethanol-based approach. [10][11][12] To investigate the uniformity of the devices, 36 TFTs with an IO active layer prepared via the aqueous route were fabricated at an The storage stability of a precursor solution is an important issue in sol-gel chemistry. The TFTs fabricated from pristine and 100-day-old aqueous solutions were compared with investigate the storage stability of the aqueous solution.…”

Section: Resultsmentioning

confidence: 99%

“…The high annealing temperature, which is usually 4400 1C, is not compatible with flexible plastic substrates, with conventional glass or with the stacked multi-layer structures because of the mismatch in the coefficient of thermal expansion between the layers during deposition. [10][11][12] A few studies on low-temperatureprocessable MOSs have been reported. [13][14][15][16] However, the authors of these studies used either complex and unstable precursors that required significant effort and multiple steps for synthesis or complicated chemical reactions that are not appropriate for the general fabrication technique.…”

Section: Introductionmentioning

confidence: 99%

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An ‘aqueous route’ for the fabrication of low-temperature-processable oxide flexible transparent thin-film transistors on plastic substrates

et al. 2013

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Metal-oxide semiconductors have attracted considerable attention as next-generation circuitry for displays and energy devices because of their unique transparency and high performance. We propose a simple, novel and inexpensive 'aqueous route' for the fabrication of oxide thin-film transistors (TFTs) at low annealing temperatures (that is, o200 1C). These results provide substantial progress toward solution-processed metal-oxide TFTs through naturally formed, unique indium complex and post annealing. The fabricated TFTs exhibited acceptable electrical performance with good large-area uniformity at low temperatures. Additional vacuum annealing facilitated the condensation reaction by effectively removing byproduct water molecules and resulted in the activation of the In 2 O 3 TFT at low annealing temperatures, even temperatures as low as 100 1C. In addition, we have demonstrated that the flexible and transparent oxide TFTs on plastic substrates exhibit good resistance to external gate bias stress. INTRODUCTIONMetal-oxide semiconductors (MOSs) are a unique class of materials that have both transparency and electronic conductivity. 1-3 Increasing demand for transparent semiconducting active materials has resulted in increased attention on the MOSs for next-generation electronics, including electronics for use in high-performance, flexible and transparent applications, because of their favorable field-effect mobility, high optical transparency and good environmental stability. 4,5 In the early studies, these materials were primarily prepared using a vacuum process. 6,7 Although the vacuum-based deposition method has advantages, the high fabrication cost and large-area device uniformity restrict its areas of application. We suggest a simple and novel 'aqueous route' for the fabrication of oxide thin-film transistors (TFTs) at low annealing temperatures (that is, o200 1C). These results provide substantial progress toward solutionprocessed metal-oxide TFTs via a unique indium complex (IC) and post annealing. In addition, we have demonstrated that the flexible and transparent oxide TFTs on plastic substrates exhibit good resistance to external gate bias stress.The solution-based synthesis approach is considered a promising solution to the issues of fabrication cost and device uniformity. This

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Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

An ‘aqueous route’ for the fabrication of low-temperature-processable oxide flexible transparent thin-film transistors on plastic substrates

et al. 2013

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“…Oregon State University and Hewlett-Packard reported the fabrication of a-ZIO TFT from a metal halide source with post-thermal annealing at 400 °C [56], and the preparation of a-ZTO and a-ZIO with thermal annealing at 500 °C [57] and a-IGZO with thermal annealing at 450 °C [58]. Recently, wet process technology has been improved signifi cantly, and the lowest annealing temperature of 280 °C and the highest mobility of 28 cm 2 /V s for 600 °C-annealed a-IGZO TFT were recently reported [59].…”

Section: Materials and Processesmentioning

confidence: 99%

Material characteristics and applications of transparent amorphous oxide semiconductors

2010

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A morphous semiconductors have created a new area of electronics known as 'giant microelectronics' typifi ed by devices such as solar cells and active-matrix (AM) fl at-panel displays. Single-crystalline semiconductor technology, typifi ed by crystal silicon electronics, is unsuitable for such applications, whereas amorphous or polycrystalline fi lms can be easily formed over large areas of greater than 1 m 2 at low temperature (e.g. < 400 °C) on both glass and plastic substrates, facilitating these new applications. Due to carrier scattering and trapping at defects on grain boundaries in polycrystalline materials (the grain boundary problem), hydrogenated amorphous silicon (a-Si:H) has been used more widely than polycrystalline silicon (p-Si) for practical large-size applications. However, the critical obstacles to be overcome to realize a-Si:H in future applications are low mobility (< 1 cm 2 /V s) and instability against electric stress and photo-illumination.In late 2004, we reported that an amorphous oxide semiconductor (AOS) with the composition a-InGaZnO 4 (a-IGZO) can be applied in the fabrication of fl exible, transparent thin-fi lm transistors (TFTs) having much improved performance compared to conventional TFTs based on a-Si:H and organic materials [1]. AOS materials have superior characteristics to conventional semiconductors, and therefore AOS TFT technology has grown very rapidly toward the realization of TFT backplanes for next-generation flat-panel displays. As summarized in Figure 1, a variety of prototype AM displays have been demonstrated by several companies within the last fi ve years since the fi rst report of AOS TFTs. Herein, we review the unique characteristics of AOS materials in relation to their TFT characteristics, and discuss why AOSs have such attractive electrical properties related to the electronic structures specifi c to transparent oxides. Active-matrix displays and circuits based on AOS TFT arraysTh e fi rst AOS-TFT was reported in late 2004 (see Figure 1). Just one year later, Toppan Printing quickly followed with the fi rst AM display based on AOS as a fl exible black-and-white electronic paper (e-paper) using a-IGZO TFTs

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“…For example, metal oxides such as zinc oxide (ZnO) [17][18][19][20][21][22] , indium oxide (In 2 O 3 ) [23][24] , indium gallium oxide (InGaO) [25] , indium zinc oxide (InZnO) [18][19][20][21][22][23][24][25][26] and zinc tin oxide (ZnSnO) [27] have been synthesised using soluble precursors and implemented into TFT structures. Despite the process simplicity, excellent charge carrier mobilities have been achieved, clearly demonstrating the significant potential of this alternative processing methodology.…”

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confidence: 99%

Spray‐Deposited Li‐Doped ZnO Transistors with Electron Mobility Exceeding 50 cm²/Vs

et al. 2010

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The ever increasing demand for high performance electronic devices that can be fabricated onto large-area substrates employing low manufacturing cost techniques has given a boost to the development of alternative types of semiconductor materials, such as organics and metal oxides, with desirable physical characteristics that are absent in their traditional inorganic counterparts. Metal oxide semiconductors, in particular, are very attractive for implementation into thin-film transistors (TFTs) [1][2] mainly because of their high charge 2 carrier mobility, high optical transparency, excellent chemical stability, mechanical stress tolerance and processing versatility [3][4][5] . Oxide semiconductors are usually grown using vacuum-based techniques such as sputtering [6][7][8] , pulsed laser deposition [9] , chemical vapour deposition [10] , and ion-assisted deposition [11][12] . Based on these methods, the synthesis of a wide range of metal oxide semiconductors with high charge carrier mobilities and low carrier concentration has been demonstrated [7] . Many of these materials have been investigated for applications in thin-film electronics where transistors with electron mobilities up to 140 cm 2 /Vs have been demonstrated [7,[11][12][13][14][15][16] . Despite the great promise however, the application of vacuum-based technologies for the deposition of complex oxide semiconductors suffers from incompatibility with large-area substrates and hence high manufacturing cost. To this end, the development of alternative deposition methods based on solution processing paradigms could provide a breakthrough in both cost and performance by marrying fabrication simplicity with high-throughput manufacturing.In recent years a wide variety of soluble precursors compounds have been examined as potential alternatives for the fabrication of oxide-based TFTs using large area deposition methods including spin casting, dip coating and spray pyrolysis. For example, metal oxides such as zinc oxide (ZnO) [17][18][19][20][21][22] , indium oxide (In 2 O 3 ) [23][24] , indium gallium oxide (InGaO) [25] , indium zinc oxide (InZnO) [18][19][20][21][22][23][24][25][26] and zinc tin oxide (ZnSnO) [27] have been synthesised using soluble precursors and implemented into TFT structures. Despite the process simplicity, excellent charge carrier mobilities have been achieved, clearly demonstrating the significant potential of this alternative processing methodology. Here we show how spray pyrolysis (SP) can be used for the deposition of doped ZnO films and the fabrication of high electron mobility TFTs onto large area substrates under ambient atmosphere. Doping is achieved by simple physical blending of the soluble precursor compounds in water or alcohol based solutions. Among the various dopants studied, transistors fabricated using Li doped ZnO were 3 found to yield the best performance with maximum electron mobility > 50 cm 2 /Vs and on/off current modulation ratio exceeding 10 6 .Preparation of the Li doped precursor solutions is described in th...

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A General Route to Printable High‐Mobility Transparent Amorphous Oxide Semiconductors

Cited by 404 publications

References 13 publications

An ‘aqueous route’ for the fabrication of low-temperature-processable oxide flexible transparent thin-film transistors on plastic substrates

An ‘aqueous route’ for the fabrication of low-temperature-processable oxide flexible transparent thin-film transistors on plastic substrates

Material characteristics and applications of transparent amorphous oxide semiconductors

Spray‐Deposited Li‐Doped ZnO Transistors with Electron Mobility Exceeding 50 cm²/Vs

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A General Route to Printable High‐Mobility Transparent Amorphous Oxide Semiconductors

Cited by 404 publications

References 13 publications

An ‘aqueous route’ for the fabrication of low-temperature-processable oxide flexible transparent thin-film transistors on plastic substrates

An ‘aqueous route’ for the fabrication of low-temperature-processable oxide flexible transparent thin-film transistors on plastic substrates

Material characteristics and applications of transparent amorphous oxide semiconductors

Spray‐Deposited Li‐Doped ZnO Transistors with Electron Mobility Exceeding 50 cm2/Vs

Contact Info

Product

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Spray‐Deposited Li‐Doped ZnO Transistors with Electron Mobility Exceeding 50 cm²/Vs