1：Experimental Design and Method Selection:

First-principles calculations based on density functional theory and the projector augmented wave method were used, implemented in the Vienna Ab initio Simulation Package (VASP). Generalized gradient approximation of Perdew, Burke, and Ernzerhof was selected for the exchange-correlation potential, with van der Waals interaction considered via the DFT-D3 approach.

2：Sample Selection and Data Sources:

Heterostructures consisting of phosphorene and B-doped graphene (P4/BC3), and B-doped phosphorene and B-doped graphene (BP3/BC3) were investigated. Specific in-plane supercells were used: (3 × 2)/(2 × 1) for P4/BC3 and (5 × 5)/(3 × 3) for BP3/BC3 to reduce lattice mismatch.

3：List of Experimental Equipment and Materials:

Computational software and codes including VASP and LOBSTER code for calculations.

4：Experimental Procedures and Operational Workflow:

Cut-off energy set to 400 eV, energy criterion of 10^-6 eV for solving Kohn-Sham equations, residual forces less than

5：01 eV/? after relaxation. A vacuum layer of 15 ? thickness was added to avoid periodic interactions. Brillouin zone integrations used 4 × 4 × 1 and 1 × 2 × 1 k-meshes for the heterostructures. Ab initio molecular dynamics simulations were performed at 300–700 K for 3 ps to confirm stability. Data Analysis Methods:

Density of states (DOS), crystal orbital Hamiltonian populations (COHP), charge density difference, Bader charge analysis, band structure calculations, effective mass, and deformation potentials were analyzed.