In this work, a simple cost-effective physical vapor deposition method for obtaining high-quality Bi 2 Se 3 and Sb 2 Te 3 ultrathin films with thicknesses down to 5 nm on mica, fused quartz, and monolayer graphene substrates is reported. Physical vapor deposition of continuous Sb 2 Te 3 ultrathin films with thicknesses 10 nm and below is demonstrated for the first time. Studies of thermoelectrical properties of synthesized Bi 2 Se 3 ultrathin films deposited on mica indicated opening of a hybridization gap in Bi 2 Se 3 ultrathin films with thicknesses below 6 nm. Both Bi 2 Se 3 and Sb 2 Te 3 ultrathin films showed the Seebeck coefficient and thermoelectrical power factors comparable with the parameters obtained for the highquality thin films grown by the molecular beam epitaxy method. Performance of the best Bi 2 Se 3 and Sb 2 Te 3 ultrathin films is tested in the two-leg prototype of a thermoelectric generator.

The majority of proposed exotic applications employing 3D topological insulators require high-quality materials with reduced dimensions. Catalyst-free, PVD-grown Bi2Se3 nanoribbons are particularly promising for these applications due to the extraordinarily high mobility of their surface Dirac states, and low bulk carrier densities. However, these materials are prone to the formation of surface accumulation layers; therefore, the implementation of surface encapsulation layers and the choice of appropriate dielectrics for building gate-tunable devices are important. In this work, all-around ZnO-encapsulated nanoribbons are investigated. Gate-dependent magnetotransport measurements show improved charge transport characteristics as reduced nanoribbon/substrate interface carrier densities compared to the values obtained for the as-grown nanoribbons on SiO2 substrates.

In this work, simple and cost‐effective phyiscal vapor deposition method is applied for deposition of single Bi2Se3, Bi1.925Sn0.075Se3, Bi2Se2.975Te0.025 ultrathin films of average thickness 10–12 nm, and for the fabrication of n‐type 5‐layer nanolaminates. The nanolaminates are composed from alternating doped and undoped ultrathin films. Electrical and thermoelectric properties (Seebeck coefficient, resistivity, electron thermal conductivity, charge carrier concentration, and mobility) of nanolaminates as well as single ultrathin undoped and doped films are studied at room temperature under ambient conditions. Both types of nanolaminates show 75–125% increase of the Seebeck coefficient accompanied by the 65–85% reduction of the electron thermal conductivity in comparison with the nanostructured bulk materials of similar chemical compositions. The mechanisms underlying such improvement of properties of studied nanolaminates in comparison with the nanostructured bulk counterparts are discussed.

Chemical vapor deposited nitrogen-doped graphene, transferred on SiO2/Si substrate was selectively patterned by femtosecond laser ablation for formation of the topology dedicated for charge carrier measurements. Ultrashort 1030 nm wavelength Yb:KGW fs-laser pulses of 22 µJ energy,14 mJ/cm 2 fluence, 96% pulse overlap and scanning speed of 100 mm/s were found to be optimum regime for the high throughput microstructure ablation in graphene, without surface damage of the substrate in the employed fs-laser micromachining workstation. Optical scanning

We propose the evaluation of strain in Bi2Se3 films based on the correlation analysis of in-plane (E2g) and out-of-plane (A21g) Raman mode positions as well as the algorithm of phonon deformation potential calculation for biaxial in-plane strain.

We used the asymmetric superconducting quantum interference device (SQUID) technique to extract the current phase relation (CPR) of a Josephson junction with a 3D-topological insulator (TI) Bi2Se3 nanobelt as the barrier. The obtained CPR shows deviations from the standard sinusoidal CPR with a pronounced forward skewness. At temperatures below 200 mK, the junction skewness values are above the zero temperature limit for short diffusive junctions. Fitting of the extracted CPR shows that most of the supercurrent is carried by ballistic topological surface states (TSSs), with a small contribution of diffusive channels primarily due to the bulk. These findings are instrumental in engineering devices that can fully exploit the properties of the topologically protected surface states of 3D TIs.

Electrochemical impedance spectroscopy was applied for studying copper oxide (CuO) nanowire networks assembled between metallic microelectrodes by dielectrophoresis. The influence of relative humidity (RH) on electrical characteristics of the CuO nanowire-based system was assessed by measurements of the impedance Z. A slight increase of Z with increasing RH at low humidity was followed by a three orders of magnitude decrease of Z at RH above 50–60%. The two opposite trends observed across the range of the examined RH of 5–97% can be caused by water chemisorption and physisorption at the nanowire interface, which suppress electronic transport inside the p-type semiconductor nanowire but enhance ionic transport in the water layers adsorbed on the nanowire surface. Possible physicochemical processes at the nanowire surface are discussed in line with equivalent circuit parameters obtained by fitting impedance spectra. The new investigation data can be useful to predict the behavior of nanostructured CuO in humid environments, which is favorable for advancing technology of nanowire-based systems suitable for sensor applications.