Charge-Density-Wave Thin-Film Devices Printed with Chemically Exfoliated 1T-TaS₂ Ink

Abstract

We report on the preparation of inks containing fillers derived from quasi-two-dimensional charge-density-wave materials, their application for inkjet printing, and the evaluation of their electronic properties in printed thin-film form. The inks were prepared by liquid-phase exfoliation of CVT-grown 1T-TaS2 crystals to produce fillers with nm-scale thickness and μm-scale lateral dimensions. Exfoliated 1T-TaS2 was dispersed in a mixture of isopropyl alcohol and ethylene glycol to allow fine-tuning of filler particles thermophysical properties for inkjet printing. The temperature-dependent electrical and current fluctuation measurements of printed thin films demonstrated that the charge-density-wave properties of 1T-TaS2 are preserved after processing. The functionality of the printed thin-film devices can be defined by the nearly commensurate to the commensurate charge-density-wave phase transition of individual exfoliated 1T-TaS2 filler particles rather than by electron-hopping transport between them. The obtained results are important for the development of printed electronics with diverse functionality achieved by the incorporation of quasi-two-dimensional van der Waals quantum materials.

Electrical Gating of the Charge-Density-Wave Phases in Two-Dimensional h-BN/1T-TaS2 Devices

“…The charge-density-wave (CDW) phase is a macroscopic quantum state consisting of a periodic modulation of the electronic charge density accompanied by a periodic distortion of the atomic lattice. − The early work on CDW effects, performed with bulk samples of the quasi-one-dimensional (1D) metallic crystals, revealed many spectacular phenomena: nonlinear electron transport, oscillating electric current for constant voltages, giant dielectric response, and multistable conducting states. − Recent years witnessed a rebirth of the field of CDW materials and devices, partially driven by an interest in layered quasi-2D van der Waals materials where CDW phases can manifest themselves at room temperature (RT) and above. − The size and geometry of quasi-2D CDW films provide compelling opportunities for device fabrication. The early studies of de-pinning of CDWs in quasi-2D materials reported certain common features among CDW phenomena in quasi-1D and quasi-2D systems. , However, there is also an understanding of differences in physics governing CDW phases in material systems of different dimensionalities and crystal structures. , …”

Quantum Composites with Charge‐Density‐Wave Fillers

“…Exfoliated 1T‐TaS 2 and other CDW van der Waals fillers can be produced via the scalable and cost‐effective LPE technique. [ 72 ] It is already being used for the processing of graphene fillers for thermal interface materials. [ 73 ] It is worth noting that 1T‐TaS 2 preserves its unique CDW properties even in powder form.…”

Robust Behavior of Charge Density Wave Quantum Motif Star‐of‐David in 2D NbSe2 Nanocrystals

“…The ordering of charge density wave (CDW) patterns in layered materials such as 1T-TaS 2 has been investigated for decades owing to its intriguing electronic state change accompanied by the structural phase transition, [1][2][3] and the promising applications in nanodevices such as field-effect transistors, [4] voltage oscillators, [5] ultrafast switches, [6,7] nonlinear thermal devices, [8] and ultrabroad band photosensitivity detector. [9] The CDW DOI: 10.1002/smll.202305159 pattern can become incommensurate or rearrange with phase slip under various stimuli such as temperature change, [10,11] pressure application, [12] doping, [13] and current or voltage pulse. [14,15] Besides, the spatial confinement of the CDW array has been investigated.…”