Low-Frequency Current Fluctuations in “Graphene-like” Exfoliated Thin-Films of Bismuth Selenide Topological Insulators

Abstract

We report on the low-frequency current fluctuations and electronic noise in thin-films made of Bi(2)Se(3) topological insulators. The films were prepared via the "graphene-like" mechanical exfoliation and used as the current conducting channels in the four- and two-contact devices. The thickness of the films ranged from ∼50 to 170 nm to avoid hybridization of the top and bottom electron surface states. Analysis of the resistance dependence on the film thickness indicates that the surface contribution to conductance is dominant in our samples. It was established that the current fluctuations have the noise spectrum close to the pure 1/f in the frequency range from 1 Hz to 10 kHz (f is the frequency). The relative noise amplitude S(I)/I(2) for the examined Bi(2)Se(3) films was increasing from ∼5 × 10(-8) to 5 × 10(-6) (1/Hz) as the resistance of the channels varied from ∼10(3) to 10(5) Ω. The obtained noise data is important for understanding electron transport through the surface and volume of topological insulators, and proposed applications of this class of materials. The results may help to develop a new method of noise reduction in electronic devices via the "scattering immune" transport through the surface states.

Surface plasmon on topological insulator/dielectric interface enhanced ZnO ultraviolet photoluminescence

“…The high-resolution TEM (HRTEM) image shown in Fig. 1(e) further indicates the mono-crystalline nature with a lattice spacing of about 0.22 nm, corresponding to the lattice spacing of (11)(12)(13)(14)(15)(16)(17)(18)(19)(20) planes of Bi 2 Te 3 . 5 The scanning electron microscope (SEM) image shown in the Supporting Information Fig.…”

“…3 The presence of the surface states on Bi 2 Se 3 and Bi 2 Te 3 have been experimentally identified by reducing the bulk conductance via tuning the gate voltage, [5][6][7] introducing dopants 8,9 or improving the sample preparation methods. 10,11 Raman spectrum and the Aharonov-Bohm effect were also used to explore the properties of surface carriers. 12,13 Recently, spin and charge collective excitation modes on the surface of a topological insulator were theoretically predicted due to the unique topological properties of the TI materials.…”

Phonon and thermal properties of exfoliated TaSe2 thin films

“…The resulting thin films can be restacked into superlattice-type structures with various properties [8,13,14]. Some of us previously have studied quintuples-five atomic layers-of bismuth telluride (Bi 2 Te 3 ), which reveal thermoelectric and topological insulator phenomena [13][14][15][16]. These quasi-2D crystals of Bi 2 Te 3 have electrical and thermal properties that are substantially different from those of bulk Bi 2 Te 3 [15,16].…”

Synthesis, characterization and electrostatic properties of WS2 nanostructures

“…Therefore, many other layered materials, such as boron nitride, 3 and topological insulators, have been prepared and extensively studied. [4][5][6] Recently, layered transition metal dichalcogenides (MX 2 (M=Mo, W; X=S, Se) have attracted a great deal of attention for their wide applications in the field of optoelectronics, 7-10 catalysis, 11, 12 energy harvesting, 8 and nano-electromechanical systems. 13 The WS 2 has a layered structure of S-W-S stacking layers made up from a basic unit cell, which is held together by van der Waals forces (Figure 1(a)).…”