1：Experimental Design and Method Selection:

The study uses a theoretical formulation based on the nonequilibrium Hubbard Green's function technique combined with first-principles calculations to model electron transport and optical response in a molecular junction. The methodology involves many-body state representation of the molecule, with parameters derived from DFT and TDDFT calculations.

2：Sample Selection and Data Sources:

A single metal-free phthalocyanine (H2Pc) molecule adsorbed on three monolayers of NaCl grown on an Ag(111) surface is used as the model system. Experimental data for comparison are obtained from STM-induced light emission measurements.

3：List of Experimental Equipment and Materials:

Scanning tunneling microscope (STM, Omicron), Ag tip, Ag(111) substrate, NaCl film, H2Pc molecules. Computational tools include Gaussian 16 software for DFT/TDDFT calculations.

4：Experimental Procedures and Operational Workflow:

For experiments, STM is operated under ultra-high vacuum at 4.7 K. Molecules are deposited on the NaCl/Ag surface, and measurements include dI/dV spectra and luminescence spectra under specific bias voltages and currents. For simulations, molecular parameters are calculated, and Hubbard NEGF is applied to compute current and photon fluxes.

5：7 K. Molecules are deposited on the NaCl/Ag surface, and measurements include dI/dV spectra and luminescence spectra under specific bias voltages and currents. For simulations, molecular parameters are calculated, and Hubbard NEGF is applied to compute current and photon fluxes. Data Analysis Methods:

5. Data Analysis Methods: Data analysis involves comparing computational results (dI/dV and luminescence spectra) with experimental data using the Hubbard NEGF method, with Franck-Condon factors and vibrational overlaps considered.