Light Absorption Near Infrared Wavelength by Laser Pulsed Texturing on Multi-crystalline Silicon Solar Cells

Abstract

In the photovoltaic (PV) sector, thin silicon (Si) wafers in multi-crystalline (mc-Si) silicon solar cells offer an option for cost-effectiveness. When the thickness of Si solar cells is less than 100 µm, however, optical loss becomes a critical factor. The silicon bandgap on the other hand is critical in the long-wavelength range of 900 to 1200 nm. As a result, it is captious to look at how to improve the cell conversion efficiency at long wavelengths.  In this paper, we were able to design and fabricate deeply etched micro-textured structure (DELMS) silicon solar cells using pulsed laser radiation. On the front surface of multi-crystalline Si solar cells, the pulsed laser energy power ranged from 15.2W (E1), 23.5W (E2), and 32.5W (E3). With specific depths, widths, and diameters of patterns applied, it boosted the internal scattering inside the sidewall of the structure of the solar cell. The infrared transmission response clearly shows that the DELMS improved the optical performance of cells in the longer wavelength. Our best samples. The short-circuit-current density, voltage open-circuit, and absolute efficiency present the improvement of ΔJ_sc= 0.5, ΔV_oc=1.83, and Δη=0.6%, respectively. The DELMS with 23.5W laser power exhibit an excellent 60.0% reduction in infrared (IR) transmission response compared with 15.2W, 32.5W, and pyramid texture.