Low-frequency noise spectroscopy of charge-density-wave phase transitions in vertical quasi-2D 1T-TaS₂ devices

Abstract

We report results regarding the electron transport in vertical quasi-2D layered 1T-TaS2 chargedensity-wave devices. The low-frequency noise spectroscopy was used as a tool to study changes in the cross-plane electrical characteristics of the quasi-2D material below room temperature. The noise spectral density revealed strong peaks -changing by more than an order-of-magnitude -at the temperatures closely matching the electrical resistance steps. Some of the noise peaks appeared below the temperature of the commensurate to nearlycommensurate charge-density-wave transition, possibly indicating the presence of the debated "hidden" phase transitions. These results confirm the potential of the noise spectroscopy for investigations of electron transport and phase transitions in novel materials. / R. Salgado et al., Low-Frequency Noise Spectroscopy of CDW Phase Transitions in Vertical Quasi-2D Devices / UCR 2 | P a g eThe 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 in metallic crystals [1][2][3]. Recently, the field of CDW materials and devices experienced a true renaissance [4][5][6][7][8][9][10][11][12][13][14][15][16]. The renewed interest has been driven by layer-control of CDW materials, such as quasi-two-dimensional (2D) crystals of 1T-TaS2 and other transition metal dichalcogenides (TMDs). Unlike classical bulk CDW materials with the quasi-1D crystalline

Low‐Frequency Electronic Noise in Quasi‐2D van der Waals Antiferromagnetic Semiconductor FePS3—Signatures of Phase Transitions

“…Details of our measurement protocol are described in the Methods section and in prior reports in the context of other materials systems. [47][48][49]51,52,[63][64][65][66][67][68][69] Measuring low-frequency noise in conductors with high electrical resistivity is challenging-one needs to have a sufficient current level to obtain reliable data. From the other side, one typically prefers to use the linear region of the I-V characteristics for biasing the device during the noise measurements.…”

“…electrical bias and temperature, can shed light on electron transport, carrier recombination mechanisms and, what is most important in this case, magnetic and metal-insulator phase transitions. [40][41][42][43][44][45][46] We have previously used successfully the low-frequency noise measurements as the "noise spectroscopy" for monitoring phase transitions in the 2D charge-density-wave materials; [47][48][49] examining the specifics of magnon transport in magnetic electrical insulators; [50] and clarifying the nature of electron transport in quasi-1D vdW materials. [51,52] Our measurements of noise in thin films of FePS 3 reveal a number of interesting features, which contribute to a better understanding of the properties of this AF vdW semiconductor.…”

Graphene as a Schottky Barrier Contact to AlGaN/GaN Heterostructures

“…The emitting diodes and displays [8], vertical graphene-based hot electron transistors [9][10][11], and phase transitions in 2D transition metal chalcogenides [12]. Another promising field, which is the topic of the current letter, is graphene electrodes for electronic devices.…”

“…A much less explored field is vertical transport through graphene and other two-dimensional materials. Indeed, there are just a few fields of research activity in this direction: transparent electrodes for light-emitting diodes and displays [8], vertical graphene-based hot electron transistors [9][10][11], and phase transitions in 2D transition metal chalcogenides [12].…”

A Two-Channel DFT Spectrum Analyzer for Fluctuation Enhanced Sensing Based on a PC Audio Board

“…Most of these interactions result in flicker (or 1/ f γ ) noise components that are more easily detected at very low frequencies where their contribution overcomes the unavoidable thermal noise components [ 14 ]. In many cases, noise measurements have proved to be decisive in understanding the detailed conduction mechanisms of electron devices [ 15 , 16 , 17 , 18 , 19 ]. This represents an invaluable feature in the process of developing emerging device technologies, whereby the clear understanding of the microscopic behavior is a key factor for the design of the next-generation devices and, clearly, it was obvious to extend this potential to advanced sensing techniques, such as the FES technique.…”