Synthesis, Properties, and Application of Ultrathin and Flexible Tellurium Nanorope Films: Beyond Conventional 2D Materials

Abstract

AbstractNanomaterials that can be easily processed into thin films are highly desirable for their wide range of applicability in electrical and optical devices. Currently, Te‐based 2D materials are of interest because of their superior electrical properties compared to transition metal dichalcogenide materials. However, the large‐scale manufacturing of these materials is challenging, impeding their commercialization. This paper reports on ultrathin, large‐scale, and highly flexible Te and Te–metal nanorope films grown via low‐power radiofrequency sputtering for a short period at 25 °C. Additionally, the feasibility of such films as transistor channels and flexible transparent conductive electrodes is discussed. A 20 nm thick Te–Ni‐nanorope‐channel‐based transistor exhibits a high mobility (≈450 cm2 V−1 s−1) and on/off ratio (105), while 7 nm thick Te–W nanorope electrodes exhibit an extremely low haze (1.7%) and sheet resistance (30 Ω sq−1), and high transmittance (86.4%), work function (≈4.9 eV), and flexibility. Blue organic light‐emitting diodes with 7 nm Te–W anodes exhibit significantly higher external quantum efficiencies (15.7%), lower turn‐on voltages (3.2 V), and higher and more uniform viewing angles than indium‐tin‐oxide‐based devices. The excellent mechanical flexibility and easy coating capability offered by Te nanoropes demonstrate their superiority over conventional nanomaterials and provide an effective outlet for multifunctional devices.