▎ 摘　　要

We study the intrinsic transport properties of suspended graphene devices at ''aigh fields Wpm) and high temperatures (>= 1000 K). Across 15 samples, we find peak (average) saturation velocity of 3.6 X 10(7) cm/s (1.7 X 107 cm/s) and peak (average) therm:.1 conductivity of 530 W K-1 (310 W ICI) at 1000 K The saturation velocity is 2 4 times and the thermal conductivity 10-17 times greater than in silicon at such elevated temperatures. However, the thermal conductivity shows a steeper di:crease at high temperature than in graphite, consistent.wift, stronger effects of secondorder three-phonon scattering. Our analysis of sample-to-sample variation suggests the behavior of "cleaner" devices most closely approaches the intrinsic high-field properties of graphene. This study reveals key features of charge and heat flow in graphene up to device breakdown at 2230 K in vacuum, highlighting remaining unknown:, under extreme operating conditions.