Platinum diselenide (PtSe₂) is an exciting new member of the two-dimensional (2D) transition metal dichalcogenide (TMD) family. It has a semimetal to semiconductor transition when approaching monolayer thickness and has already shown significant potential for use in device applications. Notably, PtSe₂ can be grown at low temperature making it potentially suitable for industrial usage. Here, we address thickness-dependent transport properties and investigate electrical contacts to PtSe₂, a crucial and universal element of TMD-based electronic devices. PtSe₂ films have been synthesized at various thicknesses and structured to allow contact engineering and the accurate extraction of electrical properties. Contact resistivity and sheet resistance extracted from transmission line method (TLM) measurements are compared for different contact metals and different PtSe₂ film thicknesses. Furthermore, the transition from semimetal to semiconductor in PtSe₂ has been indirectly verified by electrical characterization in field-effect devices. Finally, the influence of edge contacts at the metal–PtSe₂ interface has been studied by nanostructuring the contact area using electron beam lithography. By increasing the edge contact length, the contact resistivity was improved by up to 70% compared to devices with conventional top contacts. The results presented here represent crucial steps toward realizing high-performance nanoelectronic devices based on group-10 TMDs.

Terpineol leads to effective exfoliation and excitonic enhancement in solution dispersions of MoS ₂ and WS ₂ , which also yields enhancement in electronic transport properties. Such dispersions are amenable to high-performance electronic and opto-electronic devices using manufacturable routes.

We report a MoS₂/PtSe₂ heterostructure-based gas sensor for detecting trace levels of NO₂ gas at room temperature. Both MoS₂ and PtSe₂ were synthesized by mechanical exfoliation, and the heterostructure was prepared using deterministic dry transfer method. Comprehensive characterization was performed using optical microscopy, field emission scanning electron microscopy, energy-dispersive X-ray spectroscopy, high resolution transmission electron microscopy, Raman spectroscopy and atomic force microscopy. The lateral shape of the heterostructure efficiently adsorbed NO₂ molecules. The sensor exhibited limited response and recovery in dark conditions. However, under UV illumination, the sensor showed remarkable response of 2180% and 117% towards 800 ppb and 50 ppb NO₂, respectively, with complete recovery. The theoretical limit of detection was found to be 3 ppb, and the sensitivity towards NO₂ sensing was 3.217% ppb⁻¹, which is noteworthy. Furthermore, the sensor demonstrated distinct selectivity, excellent repeatability and stability. These findings are expected to significantly advance ongoing research on TMDC-based heterostructures for gas sensing application.

P-type pristine InSe, pristine graphene, and the corresponding hybrid InSe-graphene gas sensor that is highly selective to NO₂ have been developed. These materials are produced at an environmentally friendly temperature of 35 °C by the Liquid Phase Exfoliation (LPE) technique. Then their deposition was performed on alumina transducers for achieving chemoresistive gas sensors. X-ray diffraction (XRD), field-emission scanning electron microscopy (FESEM), high-resolution transmission electron microscopy (HRTEM), photoluminescence (PL), and Raman spectroscopy were used to analyze the materials. The multilayered crystalline structure is revealed by HRTEM. Studies on gas-sensing properties showed that the response of the hybrid InSe-graphene sensor to 1 ppm of NO₂ is three times higher than the one of the pristine graphene sensor, whereas the pristine InSe sensor was not responsive. While under dry conditions, the response to NO₂ (1 ppb) was 3.41%, under humid conditions (RH 50%), the responsiveness was significantly increased to 6.16% and to 14.42% for sensors operated at 150 and 250 °C, respectively.

We have observed the in-plane magnetic domain arrangement during magnetization reversal in a 40 nm thick La0.7Sr0.3MnO3/SrTiO3 (001) thin film patterned into 500 μm long microbridges of width 50 or 100 μm. Magneto-optical Kerr effect microscopy was used at room temperature and magnetic hysteresis loops were deduced from local averaging of intensity over the microbridge areas. Magnetization reversal proceeds by nucleation and propagation of 180° domain walls. When the magnetic field was applied parallel to the bridge, we observed the nucleation of only one or two domain walls and the reversal occurred by the propagation of them. When the magnetic field was applied perpendicular to the bridge, the reversal occurred mostly by the nucleation of several domain walls. The low field magnetoresistance (MR) and the low frequency noise at zero magnetic field were measured at room temperature. In addition to the linear and reversible colossal MR effect, hysteretic MR versus magnetic field curves could be observed, showing two maxima (minima) when the magnetic field is parallel (perpendicular) to the bridge length. The observed hysteretic MR behaviour is attributed to anisotropic MR inside the 180° Néel domain walls.

Unlike the most used, this study explores the effects of direct and indirect sonication methods on the dispersion and gas sensing performance of MoS₂ nanoflakes. The obtained dispersions are characterized using various techniques, such as field emission scanning electron microscopy, high resolution transmission electron microscopy, atomic force microscopy, dynamic light scattering, and Raman and X-ray diffraction, to evaluate their morphological and structural properties. Gas sensing measurements are conducted using exfoliated MoS₂ on interdigitated electrode structures, and the response to multiple gases is recorded. The sensitivity and selectivity of the sensors are analyzed and compared between the direct and indirect sonication methods. The results demonstrate that both direct and indirect methods lead to the formation of well-dispersed MoS₂ multilayer nanosheets, whereas the indirect approach exhibits a uniform and bigger flake size. Gas sensing experiments reveal that the MoS₂ nanoflakes prepared via indirect sonication have enhanced sensitivity by 17 and 46% toward NO₂ and NH₃ gases, respectively, compared to the ones achieved by the direct sonication method. Both methods demonstrated its selectivity for NO₂ and NH₃ and the preferential temperature to detect NO₂ and NH₃ gas are 50 and 100 °C, respectively. This research contributes to the development of eco-friendly MoS₂-based gas sensors by providing insights into the influence of direct (probe) and indirect (bath) sonication methods on dispersion quality and gas sensing performance. The findings highlight the potential of indirect sonication as a reliable technique for fabricating high-performance MoS₂ gas sensors, opening venues for the design and optimization of eco-friendly sensing platforms for environmental monitoring and industrial applications.