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Recent advances in the exploration of two-dimensional (2D) van der Waals (vdW) ferroelectrics revealed not only a wealth of fundamentally exciting properties but also a strong potential for nanoelectronic applications facilitated by their semiconducting nature and tunable polarization-coupled physical properties. Here, using scanning probe microscopy techniques, we investigate the effects of mechanical stress and optical illumination on the transport behavior of one of the most actively studied 2D ferroelectrics, α-In2Se3. Local I–V measurements reveal a strongly asymmetric polarization-dependent conductivity of α-In2Se3, which can be continuously tuned by the tip-induced mechanical pressure. While the local conductivity increases up to two orders of magnitude for both polarization states, the upward polarization displays a much sharper change. Further enhancement of conductivity by an order of magnitude is observed under optical illumination, resulting from a cumulative modulation of the junction barrier via polarization, strain, and optical excitation. The obtained results make α-In2Se3 a promising material for application in electronic devices with optomechanical functionality. 

Low-dimensional materials hold great promises for exploring emergent physical phenomena, nanoelectronics, and quantum technologies. Their synthesis often depends on catalytic metal films, from which the synthesized materials must be transferred to insulating substrates to enable device functionality and minimize interfacial interactions during quantum investigations. Conventional transfer methods, such as chemical etching or electrochemical delamination, degrade material quality, limit scalability, or prove incompatible with complex device architectures. Here, a scalable, etch-free transfer technique is presented, employing Field's metal (51% In, 32.5% Bi, and 16.5% Sn by weight) as a low-melting-point mechanical support to gently delaminate low-dimensional materials from metal films without causing damage. Anchoring the metal film during separation prevents tearing and preserves material integrity. As a proof of concept, atomically precise graphene nanoribbons (GNRs) are transferred from Au(111)/mica to dielectric substrates, including silicon dioxide (SiO_2) and single-crystalline lanthanum oxychloride (LaOCl). Comprehensive characterization confirms the preservation of structural and chemical integrity throughout the transfer process. Wafer-scale compatibility and device integration are demonstrated by fabricating GNR-based field-effect transistors (GNRFETs) that exhibit room-temperature switching with on/off current ratios exceeding 10^3. This method provides a scalable and versatile platform for integrating low-dimensional materials into advanced low-dimensional materials-based technologies. 

Cr₂TiC₂T_xMXene was used as an adsorbent for the trace determination of heavy metals in food samples, with LOD values of 0.09 and 1.9 ng mL⁻¹, and dynamic ranges of 0.3–90 and 6–120 μg L⁻¹for cadmium and lead ions, respectively. 

We synthesized a series of Zr_1−xTi_xS₃solid solutions (0 ≤x≤ 1)viaa direct reaction between Zr–Ti alloys and sulfur vapor at 600 °C. These solid solutions have a tunable bandgap in the 1–2 eV range that linearly increases with the Zr content. 

Monolayers of Ti3C2Tx MXene and bilayer structures formed by partially overlapping monolayer flakes exhibit opposite sensing responses to a large scope of molecular analytes. When exposed to reducing analytes, monolayer MXene flakes show increased electrical conductivity, i.e., an n-type behavior, while bilayer structures become less conductive, exhibiting a p-type behavior. On the contrary, both monolayers and bilayers show unidirectional sensing responses with increased resistivity when exposed to oxidizing analytes. The sensing responses of Ti3C2Tx monolayers and bilayers are dominated by entirely different mechanisms. The sensing behavior of MXene monolayers is dictated by the charge transfer from adsorbed molecules and the response direction is consistent with the donor/acceptor properties of the analyte and the intrinsic n-type character of Ti3C2Tx. In contrast, the bilayer MXene structures always show the same response regardless of the donor/acceptor character of the analyte, and the resistivity always increases because of the intercalation of molecules between the Ti3C2Tx layers. This study explains the sensing behavior of bulk MXene sensors based on multiflake assemblies, in which this intercalation mechanism results in universal increase in resistance that for many analytes is seemingly inconsistent with the n-type character of the material. By scaling MXene sensors down from multiflake to single-flake level, we disentangled the charge transfer and intercalation effects and unraveled their contributions. In particular, we show that the charge transfer has a much faster kinetics than the intercalation process. Finally, we demonstrate that the layer-dependent gas sensing properties of MXenes can be employed for the design of sensor devices with enhanced molecular recognition.