Light beam induced current mapping to characterize damage characteristics of silicon solar cell irradiated by continuous-wave laser

Aiming at the damage characteristics of silicon solar cells irradiated by continuous-wave (CW) laser, a light beam induced current (LBIC) mapping system was applied to characterize the damage characteristics of solar cells, and the damage characteristics were analyzed. A 1 070 nm CW laser was used to focus on the surface of silicon solar cell to induce damage. A LBIC system was use to obtain the photocurrent spatial distribution of the laser irradiation area of solar cell to analyze the damage. In order to characterize the damage of solar cell at different depths, the LBIC system used 650 nm and 980 nm lasers as probe light sources respectively. The results show that when 1 070 nm CW laser irradiates the non-finger part of a silicon solar cell, the solar cell damage first occurs inside; with the increase of power density, there is an invalid region inside the solar cell before its surface melts. When the laser irradiates fingers, the finger will melting. It will result in a decrease in the photocurrent at the side of the irradiated position which away from the electrode lead. In severe cases, the solar cell will have cracks which perpendicular to fingers, and the cracks will invalidate the cell on the side away from the electrode lead. The results can provide a reference for the research on the damage mechanism of CW laser irradiated solar cells.