Functional 2D material‐based devices are likely subjected to high ambient temperatures when integrated into miniaturized circuits for practical applications, which may induce irreversible structural changes in materials and impact the device performance. However, majority of 2D devices’ studies focus on room temperature or low‐temperature operation conditions. Here, the high‐temperature (up to 673 K) electro‐thermal response of molybdenum ditelluride (MoTe2)‐based field‐effect transistors is investigated. The optimal annealing temperature of around 500–525 K for the multilayer MoTe2 devices with two‐fold enhancement in maximum current level, field‐effect mobility, and current on‐off ratio is identified. Furthermore, MoTe2 devices show the transition of electrical response from gate modulation to the degenerately p‐doped (hole dominant) characteristics when the operation temperature increases to ≈600 K. The gate‐dependent electro‐thermal measurements complemented by surface chemistry analysis confirm the near range hopping transport in the MoTe2 channel at high temperature induced by thermally triggered oxidation of MoTe2. These results not only provide the thermal endurance limits of MoTe2 for practical applications, but also indicate the possible applications of MoTe2 for thermal sensing applications.

Engineering of the dipole and the symmetry of materials plays an important role in fundamental research and technical applications. Here, a novel morphological manipulation strategy to engineer the dipole orientation and symmetry of 2D layered materials by integrating them with 1D nanowires (NWs) is reported. This 2D InSe -1D AlGaAs NW heterostructure example shows that the in-plane dipole moments in InSe can be engineered in the mixed-dimensional heterostructure to significantly enhance linear and nonlinear optical responses (e.g., photoluminescence, Raman, and second harmonic generation) with an enhancement factor of up to ≈12. Further, the 1D NW can break the threefold rotational symmetry of 2D InSe, leading to a strong optical anisotropy of up to ≈65%. These results of engineering dipole orientation and symmetry breaking with the mixed-dimensional heterostructures open a new path for photonic and optoelectronic applications.

Mixed-dimensional heterostructures combine the merits of materials of different dimensions; therefore, they represent an advantageous scenario for numerous technological advances. Such an approach can be exploited to tune the physical properties of two-dimensional (2D) layered materials to create unprecedented possibilities for anisotropic and high-performance photonic and optoelectronic devices. Here, we report a new strategy to engineer the light−matter interaction and symmetry of monolayer MoS 2 by integrating it with one-dimensional (1D) AlGaAs nanowire (NW). Our results show that the photoluminescence (PL) intensity of MoS 2 increases strongly in the mixed-dimensional structure because of electromagnetic field confinement in the 1D high refractive index semiconducting NW. Interestingly, the 1D NW breaks the 3-fold rotational symmetry of MoS 2 , which leads to a strong optical anisotropy of up to ∼60%. Our mixed-dimensional heterostructure-based phototransistors benefit from this and exhibit an improved optoelectronic device performance with marked anisotropic photoresponse behavior. Compared with bare MoS 2 devices, our MoS 2 /NW devices show ∼5 times enhanced detectivity and ∼3 times higher photoresponsivity. Our results of engineering light−matter interaction and symmetry breaking provide a simple route to induce enhanced and anisotropic functionalities in 2D materials.

Fabricating electronic and optoelectronic devices by transferring predeposited metal electrodes has attracted considerable attention, owing to the improved device performance. However, the pre-deposited metal electrode typically involves complex fabrication procedures. Here, we introduce our facile electrode fabrication process which is free of lithography, lift-off, and reactive ion etching by directly presstransferring a single-walled carbon nanotube (SWCNT) film. We fabricated Schottky diodes for photodetector applications using dry-transferred SWCNT films as the transparent electrode to increase light absorption in photoactive MoS 2 channels. The MoS 2 flake vertically stacked with an SWCNT electrode can exhibit excellent photodetection performance with a responsivity of ∼2.01 × 10 3 A/W and a detectivity of ∼3.2 × 10 12 Jones. Additionally, we carried out temperature-dependent current− voltage measurement and Fowler−Nordheim (FN) plot analysis to explore the dominant charge transport mechanism. The enhanced photodetection in the vertical configuration is found to be attributed to the FN tunneling and internal photoemission of charge carriers excited from indium tin oxide across the MoS 2 layer. Our study provides a novel concept of using a photoactive MoS 2 layer as a tunneling layer itself with a dry-transferred transparent SWCNT electrode for high-performance and energy-efficient optoelectronic devices.