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.

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.