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The polymorphic transition from 2 H to 1$${T}^{{\\prime} }$$T ′ -MoTe 2 , which was thought to be induced by high-energy photon irradiation among many other means, has been intensely studied for its technological relevance in nanoscale transistors due to the remarkable improvement in electrical performance. However, it remains controversial whether a crystalline 1$${T}^{{\\prime} }$$T ′ phase is produced because optical signatures of this putative transition are found to be associated with the formation of tellurium clusters instead. Here we demonstrate the creation of an intrinsic 1$${T}^{{\\prime} }$$T ′ lattice after irradiating a mono- or few-layer 2 H -MoTe 2 with a single field-enhanced terahertz pulse. Unlike optical pulses, the low terahertz photon energy limits possible structural damages. We further develop a single-shot terahertz-pump-second-harmonic-probe technique and reveal a transition out of the 2 H -phase within 10 ns after photoexcitation. Our results not only provide important insights to resolve the long-standing debate over the light-induced polymorphic transition in MoTe 2 but also highlight the unique capability of strong-field terahertz pulses in manipulating quantum materials.

MoTe2 has emerged as a promising candidate in the field of integrated circuits, memristive devices, and catalysts, owing to its polymorphic nature across different phases. Experimentally, strain engineering has been demonstrated as an effective approach for manipulating the phase transition of MoTe2, but the mechanism remains unclear. The strain-dependent phase transition and its micro-mechanisms have been investigated based on first principle calculations. As demonstrated, critical strain and phase transition path from H → T′ phases are strongly governed by the applied strain's orientation, magnitude, and triaxiality. At the atomic level, nonzero movements of Te atoms within the phase transition domain with mechanical unloading have been clarified, together with an advanced understanding on the impact of strain on Te-vacancies migration. These insights advanced the knowledge of MoTe2 phase transition behavior and demonstrated the large space to explore potential applications through strain, defect, and phase engineering.

This study investigates the adsorption characteristics of the pristine MoTe2 monolayer and the metal atom (Co, V, W, Zr)-modified MoTe2 monolayer on the hazardous gases CO, CH3CHO, and C6H6 based on the density functional theory. The adsorption mechanism was studied from the perspectives of molecular density differences, band structures, molecular orbitals, and the density of states. Research analysis showed that the changes in conductivity caused by the adsorption of different gases on the substrate were significantly different, which can be used to prepare gas sensing materials with selective sensitivity for CO, CH3CHO, and C6H6. This study lays a reliable theoretical foundation for the gas sensing analysis of toxic and hazardous gases using metal atom-modified MoTe2 materials.

In the advancing field of optoelectronics, multifunctional devices that integrate both detection and processing capabilities are increasingly desirable. Here, a gate‐tunable dual‐mode optoelectronic device based on a MoTe2/MoS2 van der Waals heterostructure, designed to operate as both a self‐powered photodetector and an optoelectronic synapse, is reported. The device leverages the photovoltaic effect in the MoTe2/MoS2 PN junction for self‐powered photodetection and utilizes trapping states at the SiO2/MoS2 interface to emulate synaptic behavior. Gate voltage modulation enables precise control of the device's band structure, facilitating seamless switching between these two operational modes. The photodetector mode demonstrates broadband detection and fast response speed, while the optoelectronic synapse mode exhibits robust long‐term memory characteristics, mimicking biological synaptic behavior. This dual functionality opens new possibilities for integrating neuromorphic computing into traditional optoelectronic systems, offering a potential pathway for developing advanced intelligent sensing and computing technologies. A gate‐tunable MoTe₂/MoS₂ heterostructure‐based dual‐mode optoelectronic device functions as both a self‐powered photodetector and an optoelectronic synapse. It leverages the photovoltaic effect for photodetection and trapping states for synaptic behavior. Gate modulation enables seamless switching, paving the way for integrating neuromorphic computing into optoelectronic systems for intelligent sensing and computing applications.

In this study, electrical characteristics of MoTe2 field-effect transistors (FETs) are investigated as a function of channel thickness. The conductivity type in FETs, fabricated from exfoliated MoTe2 crystals, switched from p-type to ambipolar to n-type conduction with increasing MoTe2 channel thickness from 10.6 nm to 56.7 nm. This change in flake-thickness-dependent conducting behavior of MoTe2 FETs can be attributed to modulation of the Schottky barrier height and related bandgap alignment. Change in polarity as a function of channel thickness variation is also used for ammonia (NH3) sensing, which confirms the p- and n-type behavior of MoTe2 devices.

In this work, the adsorption and sensing behaviors of Rh-doped MoTe2 (Rh-MoTe2) monolayer upon SO2, SOF2, and SO2F2 are investigated using first-principles theory, wherein the Rh doping behavior on the pure MoTe2 surface is included as well. Results indicate that TMo is the preferred Rh doping site with Eb of − 2.69 eV, and on the Rh-MoTe2 surface, SO2 and SO2F2 are identified as chemisorption with Ead of − 2.12 and − 1.65 eV, respectively, while SOF2 is physically adsorbed with Ead of − 0.46 eV. The DOS analysis verifies the adsorption performance and illustrates the electronic behavior of Rh doping on gas adsorption. Band structure and frontier molecular orbital analysis provide the basic sensing mechanism of Rh-MoTe2 monolayer as a resistance-type sensor. The recovery behavior supports the potential of Rh-doped surface as a reusable SO2 sensor and suggests its exploration as a gas scavenger for removal of SO2F2 in SF6 insulation devices. The dielectric function manifests that Rh-MoTe2 monolayer is a promising optical sensor for selective detection of three gases. This work is beneficial to explore Rh-MoTe2 monolayer as a sensing material or a gas adsorbent to guarantee the safe operation of SF6 insulation devices in an easy and high-efficiency manner.

Two-dimensional (2D) transition metal dichalcogenides (TMDCs) have layered structures with excellent tribological properties. Since the energy difference between hexagonal-molybdenum ditelluride (2H-MoTe 2 ) and distorted octahedral-molybdenum ditelluride (1T’-MoTe 2 ) is very small among the transition metal dichalcogenides (TMDCs), MoTe 2 becomes one of the most promising candidates for phase engineering. In our experiment, we found that the friction force and friction coefficient (COF) of 2H-MoTe 2 were an order of magnitude smaller than those of 1T’-MoTe 2 by the atomic force microscope (AFM) experiments. The friction difference between 1T’-MoTe 2 and 2H-MoTe 2 was further verified in molecular dynamics (MD) simulations. The density functional theory (DFT) calculations suggest that the friction contrast is related to the difference in sliding energy barrier of the potential energy surface (PES) for a tip sliding across the surface. The PES obtained from the DFT calculation indicates that the maximum energy barrier and the minimum energy path (MEP) energy barrier of 2H-MoTe 2 are both smaller than those of 1T’-MoTe 2 , which means that less energy needs to be dissipated during the sliding process. The difference in energy barrier of the PES could be ascribed to its larger interlayer spacing and weaker Mo–Te interatomic interactions within the layers of 2H-MoTe 2 than those of 1T’-MoTe 2 . The obvious friction difference between 1T’-MoTe 2 and 2H-MoTe 2 not only provides a new non-destructive means to detect the phase transition by the AFM, but also provides a possibility to tune friction by controlling the phase transition, which has the potential to be applied in extreme environments such as space lubrication.

Detecting the characteristic decomposition products (SO2, SOF2, and HF) of SF6 is an effective way to diagnose the electric discharge in SF6-insulated equipment. Based on first-principles calculations, Au, Ag, and Cu were chosen as the surface modification transition metal to improve the adsorption and gas-sensing properties of MoTe2 monolayer towards SO2, SOF2, and HF gases. The results show that Au, Ag, and Cu atoms tend to be trapped by TH sites on the MoTe2 monolayer, and the binding strength increases in the order of Ag < Au < Cu. In gas adsorption, the moderate adsorption energy provides the basis that the TM-MoTe2 monolayer can be used as gas-sensing material for SO2, SOF2, and HF. The conductivity of the adsorption system changes significantly. The conductivity decreases upon gases adsorption on TM-MoTe2 monolayer, except the conductivity of Ag-MoTe2 monolayer increases after interacting with SOF2 gas.

In the past decade, molybdenum ditelluride (MoTe2) has received significant attention from the scientific community due to its structural features and unique properties originate from them. In the current review, the properties, various preparation approaches, and versatile applications of MoTe2 are presented. The review provides a brief update on the state of our fundamental understanding of MoTe2 material and also discusses the issues that need to be resolved. To introduce MoTe2, we briefly summarize its structural, optoelectronic, magnetic, and mechanical properties in the beginning. Then, different preparation methods of MoTe2, such as exfoliation, laser treatment, deposition, hydrothermal, microwave, and molecular beam epitaxy, are included. The excellent electrical conductivity, strong optical activity, tunable bandgap, high sensitivity, and impressive stability make it an ideal contender for different applications, including energy storage, catalysis, sensors, solar cells, photodetectors, and transistors. The performance of MoTe2 in these applications is systematically introduced along with mechanistic insights. At the end of the article, the challenges and possible future directions are highlighted to further modify MoTe2 material for the numerous functionalities. Therefore, the availability of different phases and layer structures implies a potential for MoTe2 to lead an era of two‐dimensional materials that began from the exfoliation of graphene. The purpose of this review paper was to provide fundamental information about MoTe2 with an emphasis on its properties, different methods of synthesis, and applications in a variety of fields. The availability of various phase structures with unique optoelectronic properties as well as its modificable layered structure makes MoTe2 material special for next‐generation advanced devices.

IMPACT STATEMENT The study explores the electronic properties of monolayer MoTe2, revealing intrinsic defects that can enhance its potential for electronic applications and providing theoretical support for defect engineering in 2D materials.