Fully transparent flexible transistors built on metal oxide nanowires

Abstract

Transparent electronics has attracted great research efforts in recent years due to its potential to make significant impact in many area, such as next generation displays, ultraviolet (UV) detectors, solar cells, charge-coupled devices (CCDs), and so on. Central to the realization of transparent electronics is the development of high performance fully transparent thin-film transistors (TFTs). One-dimensional (1-D) nanostructures have been the focus of current researches due to their unique physical properties and potential applications in nanoscale electronics and optoelectronics. Among 1-D nanostructures, transparent metal oxide nanowires are one of the best candidates to make fully transparent TFTs. We provide in this paper the most recent development on the fabrication of fully transparent TFT using metal oxide nanowires as the device elements. First, the review article gives a general introduction about the development of transparent electronics using different kinds of materials as the devices elements, including organic semiconductors, metal oxide thin films, and metal oxide nanowires. Second, the growth of metal oxide nanowires using vapor phase methods governed by two different growth mechanisms: vaporsolid mechanism and vapor-liquid-solid mechanism, respectively, are described. Third, the fabrication of transparent and flexible TFTs using different metal oxides nanowires is comprehensively described. In conclusion, the challenges and prospects for the future are discussed.

Transparent Silver-Nanoparticles/Nanorods-Decorated Zinc Oxide Nanowires

“…During our synthesis, it is inevitable to dope ZnO nanowires with Ag at high reaction temperature, although we did not detect any signal from Ag element in Figure g. This result is similar to the other work on doped metal oxide nanowires. ,, …”

“…[11][12][13][14][15] One efficient way to improve the performance of 1-D TCO devices is to dope 1-D TCO nanostructures with proper dopants, which is of great significance for both technological applications and fundamental understanding. 11,13,16,17 For example, Lu et al synthesized Sn-doped In 2 O 3 (ITO) nanowire arrays, which show a very low resistivity of 6.29 × 10 -5 Ωcm and a high failurecurrent density of 3.1 × 10 7 A/cm 2 . Transparent metallic Sbdoped SnO 2 nanowires, In-doped ZnO nanowires, and so forth were also studied for the purpose of high-performance TCO devices.…”

Ecofriendly Water-Based Solution Processing: Preliminary Studies of Zn-ZrO2 Thin Films for Microelectronics Applications

“…On the other hand, doping of Zn extends the band tail further into the bandgap of ZrO 2 by adding more defect states, which makes the band edge more blurred, indicated by Figure 5b. This is further confirmed by implementing Equation (2), in order to evaluate E U , for each sample, to investigate the formation of band tailing into the energy gap of ZrO 2 as a result of Zn doping. The value of E U was calculated as 1/m where m is the slope of linear fit obtained from ln(α) against E curve plotted in close proximity to the fundamental absorption region.…”

“…As the doping level is varied, a red shift in the absorption edge is observed, which also identifies the corresponding decrease in the band gap energy (Eg). The direct band gap energy (Eg) values, listed in Table 2, were assessed using the well-known Tauc method by extrapolating the linear segment of the (αE) 2 versus the E curve for each sample, as shown in Figure 5b. The absorption coefficient (α) was calculated from the following expression, for each sample.…”

“…The advent of modern transparent technology is owed to the development of metal oxide-based materials, especially semiconductors. The transparent metal oxides proffer the future prospect of low-cost microelectronics [1] and the next-generation optical displays [2][3][4] with improved characteristics such as high (>80%) transparency (due to their wide optical bandgap > 3 eV in general), large carrier mobilities, and ease of processing. Zirconia (ZrO 2 ) is not only a wide band gap (3-7.8 eV) [5,6] and highly stable metal oxide, but it exhibits larger values of both refractive index and dielectric constant that make it aptly suitable for a great range of applications.…”