<p>Heterostructuring of two monolayers is highly significant in modern science and nanotechnology and enables the design of materials with tailored electronic, optical, and mechanical properties. This study explores the work function modulation of monolayer graphene, hexagonal boron nitride (h-BN), and their bilayer heterostructure (graphene/h-BN) under ultrafast laser irradiation. Using time-dependent density functional theory (TDDFT) and real-time simulations, we systematically investigate how laser intensity, frequency, and polarization influence the electronic properties of these materials. The results demonstrate that ultrafast laser irradiation induces pronounced nonlinear effects, including band gap reduction and work function tuning. Specifically, increasing laser intensity lowers the work function, while higher frequencies and changes in the electric field direction elevate it. Notably, in the graphene/h-BN heterostructure, when irradiated with an electric field perpendicular to the plane, the work function decreases compared to its individual monolayers. In contrast, an electric field parallel to the plane significantly increases the work function. These effects arise from laser-induced charge redistribution and interlayer interactions, which play a crucial role in modulating the heterostructure’s electronic properties. Our findings highlight the potential of ultrafast lasers as a versatile tool for dynamically controlling the work function and electronic structure of 2D materials.</p>