Abstract <p>It is crucial to optimize the thermophotovoltaic (TPV) thermal emitter to enhance energy conversion. In this work, the optimization of the thermal emitter is achieved through changing the layer thicknesses and the material arrangement of the thermal emitter. The transfer matrix method (TMM) and the simulated annealing algorithm (SAA) are integrated to achieve an optimal thermal emitter. By searching for the global optimal solution, the SAA can ultimately achieve an optimal multilayer thermal emitter structure with the value of figure of merit (FOM) = 85.34%, which is greatly surpassing most previous works. The optimal thermal emitter is comprised of three materials: Si, SiO₂, and W. The material W (105 nm) is as the base, and the optimal TPV thermal emitter structure is: Si&#xa0;(15 nm), SiO₂ (35 nm), Si (35 nm), W (15 nm), Si (15 nm), W (24 nm), Si (35 nm) from top to bottom. After optimizing the structure, this work conducted a detailed analysis of the physical mechanism and the theoretical efficiency of TPV system. More specifically, this work provides an insight into the mechanism through electric and magnetic fields of optimal thermal emitter at 570 and 1510 nm wavelengths. Related physical properties reveal that the incident spectral energy of this thermal emitter is almost below the bandgap wavelength of photovoltaic cell. Upon evaluating the system efficiency and theoretical emissivity of this TPV thermal emitter, it is found that the TPV thermal emitter exhibits superior system performance. This work paves the way for the design of a thermophotovoltaic thermal emitter.</p>