Аннотация
This paper presents a mathematical modeling study of photocurrent density enhancement in silicon solar cells subjected to laser surface modification. The effects of femtosecond and nanosecond laser pulses on the formation of surface micro- and nanostructures, which determine the optical properties of the material and the efficiency of photocarrier generation, are investigated. The developed model is based on a comprehensive consideration of laser–semiconductor interaction, heat transfer, surface morphology evolution, and spectral characteristics of reflection and absorption. It is shown that nanosecond laser pulses mainly lead to thermal modification of the surface, including melting and recrystallization, whereas femtosecond pulses enable the formation of subwavelength nanostructures due to non-equilibrium processes and strong energy localization. It is established that laser surface modification reduces the reflectance of silicon from 0.30–0.35 to 0.12–0.18 for nanosecond treatment and to 0.04–0.08 for femtosecond treatment, accompanied by an increase in the absorption coefficient up to 92–96 %. The modeling results demonstrate that enhanced light absorption leads to an increase in photocurrent density by 15–25 % for nanosecond processing and by 30–40 % for femtosecond processing. The obtained results confirm that laser-induced nanostructuring is an effective method for increasing photocurrent and improving the efficiency of silicon solar cells. Keywords: silicon solar cells; photocurrent; laser surface modification; femtosecond pulses; nanosecond pulses; nanostructures; reflectance; light absorption.