Versatile Metal Oxide Nanowire Devices Achieved via Controlled Doping
- PDF / 1,929,634 Bytes
- 6 Pages / 612 x 792 pts (letter) Page_size
- 59 Downloads / 165 Views
1018-EE11-06
Versatile Metal Oxide Nanowire Devices Achieved via Controlled Doping Eric Dattoli, Qing Wan, and Wei Lu Electrical Engineering and Computer Science, University of Michigan, 1301 Beal Ave., Ann Arbor, MI, 48109 ABSTRACT We report on studies of field-effect transistor (FET) and transparent thin-film transistor (TFT) devices based on lightly Ta-doped SnO2 nanowires. Uniform device performance was obtained using an in situ doping method, with average field-effect mobilities exceeding 100 cm2/(Vïs). Prototype fully-transparent TFT devices on glass substrates showed excellent performance metrics in terms of transconductance and on/off ratio. The combined advantages of SnO2 nanowires: namely a low cost growth process, high electron mobility, and optical transparency; make the system well suited for large-scale transparent electronics on lowtemperature substrates. INTRODUCTION Owing to their simple growth procedure and attractive electrical and optical properties (i.e. high electron mobility and optical transparency), metal oxide nanowires have gained much attention recently [1]. However, in order to be used as an electronic material, a reliable and finely controlled doping procedure is of critical importance. The in situ doping of metal oxide nanowires during growth has been shown to dramatically affect these materialsí electrical properties. For instance, the heavy doping of In2O3 nanowires was previously demonstrated to produce nanowires with resisitivites as low as the best Sn-doped In2O3 (ITO) thin films [2]. In this work, we report on the performance of lightly Ta-doped SnO2 nanowires fabricated into nanowire field-effect (FET) and thin-film transistors (TFT). The obtained device performance and field-effect mobilities, which exceed 100 cm2/(Vïs), surpass the performance of existing amorphous semiconductor thin-films. These results indicate the future capability of doped SnO2 nanowires as a high performance material for electronic applications. Metal oxide nanowires possess several properties which are suitable for large-area electronic applications. The simple vapor transport synthesis method allows for the growth of large quantities of single-crystalline nanowires in high-temperature furnaces [1-3]. In particular, the growth and material cost for SnO2 nanowires is lower than that of indium or silicon based nanowires, or carbon nanotubes. Following growth, these nanowires may be transferred to virtually any substrate, and devices can be fabricated on the nanowire ìfilmsî at low temperatures on a variety of substrates (i.e. plastic) [4]. Due to the crystalline nature of the transport channel, these nanowire-based thin film devices will be capable of achieving larger carrier mobilities as compared with conventional amorphous thin-film and organic semiconductors. Moreover, the high optical transmittance of SnO2 nanowires, coupled with the ease of obtaining Ohmic contacts with conventional transparent conducting oxide films, suggests that SnO2 nanowires may be suitable for a number of applications includin
Data Loading...
