Flexible transparent heteroepitaxial conducting oxide with mobility exceeding 100 cm2 V−1 s−1 at room temperature

Flexible and transparent applications have become an emerging technology and have shifted to the forefront of materials science research in recent years. Transparent conductive oxide films have been applied for flat panel displays, solar cells, and transparent glass coatings. However, none of them can fulfill the requirements for advanced transparent flexible devices, such as high-frequency applications. Here, we present a promising technique for transparent flexible conducting oxide heteroepitaxial films: the direct fabrication of epitaxial molybdenum-doped indium oxide (IMO) thin films on a transparent flexible muscovite substrate. An n-type epitaxial IMO film is demonstrated with a mobility of 109 cm2 V−1 s−1, a figure of merit of 0.0976 Ω−1, a resistivity of 4.5 × 10−5 Ω cm and an average optical transmittance of 81.8% in the visible regime. This heteroepitaxial system not only exhibits excellent electrical and optical performance but also shows excellent mechanical durability. Our results illustrate that this is an outstanding way to fabricate transparent and flexible conducting elements for the evolution and expansion of next-generation smart devices. A thin, flexible material that is transparent and can conduct an electrical current has been developed by scientists in Taiwan. Materials with flexibility, transparency and conductivity are useful for wearable optoelectronics, but are rare. Indium tin oxide is a widely used transparent conductor, but when used in thin layers its electrical properties are not good enough for efficient thin-film transistors, thin-film solar cells and high-frequency devices. Ying-Hao Chu and co-workers from the National Chiao Tung University in Hsinchu used a technique called radio-frequency magnetron sputtering to deposit a thin film of indium oxide containing small amounts of molybdenum on a substrate. Measurements showed that the films had high charge mobility at room temperature, low electrical resistivity, and optical transparency, indicating that the material could be used in the next generation of smart devices. We present a promising technique for transparent flexible conducting oxide heteroepitaxial films: the direct fabrication of epitaxial molybdenum-doped indium oxide (IMO) thin films on a transparent flexible muscovite substrate. An n-type epitaxial IMO film is demonstrated with a mobility of 109 cm2 V−1 s−1, a figure of merit of 0.0976 Ω−1, a resistivity of 4.5 × 10−5 Ω cm and an average optical transmittance of 81.8% in the visible regime. IMO heterostructure not only exhibits excellent performance but also shows excellent mechanical durability. This study demonstrated an extraordinary achievement for the evolution and expansion of next-generation smart devices.