Additive manufacturing plays a crucial role in next-generation solar cells, enabling multi-layer deposition required for heterojunction and intermediate band solar cells. In this context, laser sintering provides precise, localized heating mechanism, minimizing thermal damage to surrounding regions. This study presents a numerical simulation of copper metallization via CO₂ laser sintering, focusing on selecting operating parameters to enhance sintering efficiency while reducing substrate damage.

The computational model, developed in ANSYS Fluent, integrates heat transfer, mass transport, and phase change phenomena. The Volume of Fluid (VOF) method is used to track the free surface evolution of the deposited nanopaste, while a Gaussian laser beam is modeled by solving the radiative transfer equation (RTE) to simulate heat absorption and reflection by the cooper nanopaste. The thermal analysis considers conduction, convection, radiation, and evaporation, along with temperature-dependent physical properties. User-Defined Functions (UDFs) introduce source terms into the energy and mass transport equations for a more accurate representation of the process.

The results provide temperature distributions, and sintering conditions, evaluating the effects of laser power and scanning speed on the sintering of copper nanoparticles. The computational model is validated by comparing the predicted temperature with experimental data obtained using infrared thermography.

This work advances numerical modeling for laser sintering for metal nanoparticles, contributing to high-precision copper metallization for advanced electronics and photovoltaics. The findings support future improvements in solar cell efficiency and cost reduction in manufacturing solar cells and other optoelectronic devices.