As the demand for reliable high-performance nanoelectronics grows, comprehensive research on time-resolved nanoscale thermal detection in operating devices is becoming urgent. Here, we employ scanning thermal microscopy (SThM) to investigate the real-time thermal response of graphene field-effect transistors (GFETs), further exhibiting their potential application in advanced electric-thermal communication. Revealed by in situ nanoscale temperature images, the full width at half maximum of hotspot in the GFET channel is 700 nm approximately, approaching the diffraction limit of traditional optics. The average temperature of device channel is proportional to the electric power from gate voltage, which manipulates the carrier concentration. Furthermore, a controllable management to the hotspot distribution is achieved successfully by adjusting the gate voltage in GFET. Profited from precise characterization and effective control of thermal distribution, the thermal response of GFET under 100 Hz voltage modulation is real-time monitored via SThM. Notably, the thermal response speed of GFET reaches up to 1 ms during our measurement, empowering outstanding capability for electric-thermal communication across various frequency modulations. This rapid thermal response might be attributed to excellent thermal conductivity and low specific heat capacity of graphene. Our findings highlight the potential of SThM in rapid and sensitive thermal response detection based on graphene nanoelectronics, which also potentially opens up new possibilities for more efficient and precise electric-thermal communication in the future.

Thermal interface materials (TIMs) with high through-plane thermal conductivity are urgently desired to avoid overheating of high-power density electronics. Introducing and aligning fillers in polymer matrixes via magnetic field is a promising method to improve the thermal conductivity of the polymer. However, either the fillers need to be modified with magnetic particles or a strong magnetic field is needed for good alignment in high filler content. This prevents further improvement of the through-plane thermal conductivity. Herein, mesophase pitch-based carbon fibers (MPCFs) with a content as high as 76 wt.% are aligned vertically in water-soluble polyvinyl alcohol (PVA) under a low magnetic field (~ 0.4 T), forming a vertically aligned MPCF (VAMPCF)/PVA composite with an extraordinary through-plane thermal conductivity of 86 W/(m·K), which is higher than that of many alloys. In addition, both theoretical and experimental results demonstrate that the critical intensity of the magnetic field needed for good alignment of the fillers depends on their size and magnetic susceptibility. Furthermore, the water solubility of PVA makes it easy to recycle MPCFs. This study offers an inspired venue to develop excellent and eco-friendly TIMs to meet ever increasing demand in heat dissipation for electronics.

With the packing density growing continuously in integrated electronic devices, sufficient heat dissipation becomes a serious challenge. Recently, dielectric materials with high thermal conductivity have brought insight into effective dissipation of waste heat in electronic devices to prevent them from overheating and guarantee the performance stability. Layered CrOCl, an anti-ferromagnetic insulator with low-symmetry crystal structure and atomic level flatness, might be a promising solution to the thermal challenge. Herein, we have systematically studied the thermal transport of suspended few-layer CrOCl flakes by micro-Raman thermometry. The CrOCl flakes exhibit high thermal conductivities along zigzag direction, from ~ 392 ± 33 to ~ 1,017 ± 46 W·m⁻¹·K⁻¹ with flake thickness from 2 to 50 nm. Besides, pronounced thickness-dependent thermal conductivity ratio ( ${\kappa }_{\mathrm{Z}\mathrm{Z}}$/ ${\kappa }_{\mathrm{A}\mathrm{R}}$ from ~ 2.8 ± 0.24 to ~ 4.3 ± 0.25) has been observed in the CrOCl flakes, attributed to the discrepancy of phonon dispersion and phonon surface scattering. As a demonstration to the heat sink application of layered CrOCl, we then investigate the energy dissipation in graphene devices on CrOCl, SiO₂ and hexagonal boron nitride (h-BN) substrates, respectively. The graphene device temperature rise on CrOCl is only 15.4% of that on SiO₂ and 30% on h-BN upon the same electric power density, indicating the efficient heat dissipation of graphene device on CrOCl. Our study provides new insights into two-dimentional (2D) dielectric material with high thermal conductivity and strong anisotropy for the application of thermal management in electronic devices.

Energy dissipation has always been an attention-getting issue in modern electronics and the emerging low-symmetry two-dimensional (2D) materials are considered to have broad prospects in solving the energy dissipation problem. Herein the thermal transport of a typical 2D ternary chalcogenide Ta₂NiS₅ is investigated. For the first time we have observed strongly anisotropic in-plane thermal conductivity towards armchair and zigzag axes of suspended few-layer Ta₂NiS₅ flakes through Raman thermometry. For 7-nm-thick Ta₂NiS₅ flakes, the ${\kappa }_{\mathrm{z}\mathrm{i}\mathrm{g}\mathrm{z}\mathrm{a}\mathrm{g}}$ is 4.76 W·m⁻¹·K⁻¹ and ${\kappa }_{\mathrm{a}\mathrm{r}\mathrm{m}\mathrm{c}\mathrm{h}\mathrm{a}\mathrm{i}\mathrm{r}}$ is 7.79 W·m⁻¹·K⁻¹, with a large anisotropic ratio ( ${\kappa }_{\mathrm{a}\mathrm{r}\mathrm{m}\mathrm{c}\mathrm{h}\mathrm{a}\mathrm{i}\mathrm{r}}/{\kappa }_{\mathrm{z}\mathrm{i}\mathrm{g}\mathrm{z}\mathrm{a}\mathrm{g}}$) of 1.64 mainly ascribed to different phonon mean-free-paths along armchair and zigzag axes. Moreover, the thickness dependence of thermal anisotropy is also discussed. As the flake thickness increases, the ${\kappa }_{\mathrm{a}\mathrm{r}\mathrm{m}\mathrm{c}\mathrm{h}\mathrm{a}\mathrm{i}\mathrm{r}}/{\kappa }_{\mathrm{z}\mathrm{i}\mathrm{g}\mathrm{z}\mathrm{a}\mathrm{g}}$ reduces sharply from 1.64 to 1.07. This could be attributed to the diversity in phonon boundary scattering, which decreases faster in zigzag direction than in armchair direction. Such anisotropic property enables heat flow manipulation in Ta₂NiS₅ based devices to improve thermal management and device performance. Our work helps reveal the anisotropy physics of ternary transition metal chalcogenides, along with significant guidance to develop energy-efficient next generation nanodevices.

Improving thermal transport between substrate and transistors has become a vital solution to the thermal challenge in nanoelectronics. Recently 2D WTe₂ has sparked extensive interest because of heavy atomic mass and low Debye temperature. Here, the thermal transport of supported WTe₂ was studied via Raman thermometry with electrical heating. The supported 30 nm WTe₂ encased with 70 nm Al₂O₃ delivered 4.8 W·m^-1·K^-1 in-plane thermal conductivity along zigzag direction at room temperature, which was almost 1.6 times larger than that along armchair direction (3.0 W·m^-1·K^-1). Interestingly, the superior and inferior directions for thermal transport are just opposite of those for electrical transport. Hence, a heat manipulation model in WTe₂ FET device was proposed. Within the designed configuration, waste heat in WTe₂ would be mostly dissipated to metal contacts located along zigzag, relieving the local temperature discrepancy in the channel effectively and preventing degradation or breakdown. Our study provides new insight into thermal transport of anisotropic 2D materials, which might inspire energy-efficient nanodevices in the future.