At this point we applied for patents and then submitted our paper to Nature, which was published in 2004. A thin-film transistor (TFT) is a type of field-effect transistor that is usually used in a liquid crystal display (LCD). We also found that TFTs fabricated on plastic substrates offered almost identical performance (Fig. The electron concentrations in the resulting a-IGZO thin films, which were deposited on glass substrates at room temperature, were below 10 16 cm –3 and the TFTs exhibited mobilities of approximately 10 cm 2 V –1 s –1 - an order of magnitude larger than that of a-Si:H TFTs. We then fabricated thin films using amorphous InGaZnO 4 (a-IGZO). As expected, the carrier concentration in epitaxial InGaO 3(ZnO) 4 reduced to a suitable level, and when applied in TFTs showed excellent performance, with a mobility of approximately 80 cm 2 V –1 s –1. To enable the adoption of organic thin-film transistors (TFT) in high-frequency device applications, the contact resistance must be reduced well below the smallest values reported to date 1,2,3. TFT technology provides optimum resolutions and. We tested InGaO 3(ZnO) m epitaxial films, where m = 4 and 5, as I believed the unique local structure around Ga 3+ would help lower the carrier concentration. A type of LCD in which each pixel is controlled by from one to four transistors. Indium oxide is a typical transparent conductive oxide with a large mobility, but reducing its excessive carrier concentration is difficult due the ease with which oxygen vacancies form. Thin film transistors (TFT) are a significant part of microelectronic devices switching or amplifying electronic signals. To develop high-mobility TFTs using transparent conductive oxides, the major issue was their high carrier concentrations (the TFTs can’t be turned off). By 2004, for example, the paper had received only 4 citations, and 2 of those were self-citations!Īfter a few years verifying the validity of the hypothesis, we started research on transparent oxide TFTs.

The idea and experimental results were published in the May issue of the Journal of Non-Crystalline Solids in 1996, but gained little interest from the research community. Testing their Hall mobility, these amorphous thin films showed values higher than 10 cm 2 V –1 s –1, which is comparable to polycrystalline thin films. To verify this hypothesis, I, together with my research group, selected and sputtered a range of metal oxide thin films, including CdO–GeO 2. As such, I hoped that when going from their ordered crystalline state to their disordered amorphous state, these oxide semiconductors might still show a high mobility. The goals of this project are the optimization of organic thin-film transistors (TFTs) and the advancement of organic-TFT-based analog and mixed-signal. In certain oxide materials containing p-block metal cations, the vacant metal s-orbital that predominantly makes up the conduction band minimum is spherical and spatially spread, making their overlap insensitive to bonding angle variation. I thought an ionic semiconductor with a wide bandgap might be different because the conduction and valence bands are made up of orbitals that have different characteristics.

Tft thin film transistor