Photovoltaic (PV) cells convert only a small part of solar energy into electricity. The rest of solar energy is dissipated into heat leading to an increase of PV cells temperature. It is well established that temperature increase negatively affects the electrical yield of the cells. As PV panels are constituted of several PV cells which are mounted in series or parallel, the PV panels' efficiency is therefore damaged by the increase of temperature. To study the coupled electrical yield and thermal behavior of PV panels, multi-physics models were developed. The models generally combine an electrical model with a thermal one. However, the photons wavelength effects are not accounted for in most of the models proposed in the literature. To account for this, we propose to use the Markov chain process for building an optical model. Therefore, the proposed multi-physics approach was developed by coupling three models: optical, electrical and thermal models. This proposed multi-physics approach was numerically implemented in the MATLAB software. The model was next applied to commercial silicon PV panels to predict their electrical and thermal behavior under Normal Operating Conditions Temperature (NOCT) conditions. The predicted results are compared to the manufacturer data sheets to validate the model. Finally, The thermal and electrical behaviors were also predicted under different irradiance levels.