Supplement Number 1

The calculated lattice constants, effective mass, deformation potential, carrier mobility, relaxation time, and mechanical property parameters of (AlxGa1-x)2O3, Ga2O3, and (InxGa1-x)2O3 monolayers, as listed in the tables. Additionally, property data for the Ga2O3 monolayer under biaxial strains ranging from -3% to 3% are also provided.