Influence of front surface single-pulse laser drilling on a bifacial solar cell determined through simulation and experiment

Abstract

This study presents the impact of surface modification on bifacial solar cells through single-pulse drilling to enhance efficiency and optical characterisation. A single-pulse laser operates at a wavelength of 1.06 μm, and the microsecond length is a function of its energy and structure setup. The front surface is drilled with two laser energy settings, namely, 23.5 W and 39.6 W, to create a range of micro-holes with distinct depths, widths and crystallographic defects. The modification of the front laser surface has enhanced current density and effectiveness by capturing light in the crystallisation region and the inner region of the micro-holes. Cell topography shift reduces the recombination of electron/hole on the surface. The rear surface registers efficiency digression because of a crystallographic defect that increases optical losses that boost the recombination of hole/electron. The efficiency of the cell with low-power front surface laser drilling increases 1.38%, but that of the cell with low-power back surface laser drilling drops 2.12%. High-power laser drilling increases 1.46% for the front surface and decreases 1.36% for the back surface. Optical characterisation via infrared transmission shows that light increment at a wavelength of 1100 nm is transmitted through the laser drill’s micro-holes. The different depths and widths of the micro-holes determine the light transmission rate that can travel to the back surface. The growth of holes improves the light-scattering and absorption regions, affecting cell efficiency.