▎ 摘　　要

In this work, we study the high critical breakdown field in beta-Ga2O3 perpendicular to its (100) crystal plane using a beta-Ga2O3/graphene vertical heterostructure. Measurements indicate a record breakdown field of 5.2 MV/cm perpendicular to the (100) plane that is significantly larger than the previously reported values on lateral beta-Ga2O3 field-effect-transistors (FETs). This result is compared with the critical field typically measured within the (100) crystal plane, and the observed anisotropy is explained through a combined theoretical and experimental analysis. Published by AIP Publishing.