Laser Induced Periodic Surface Structured c-Si Solar Cell with more than 16% efficiency

Crystalline-Si (c-Si) based solar cells (SC) efficiency remains one of the most challenging part in photovoltaic industry. Besides of the thermodynamical limits, the optical losses due to indirect band-gap structure of the material require additional treatment which known as a photonic design of the SC surface [1] . Numerous manipulations are performed to increase the efficiency of commercial solar cells. In most of these methods, the main concept is increasing light interaction by the cell through chemical modification of the morphology of the surface. Creation of pyramid-like structure on SC surface through the chemical etching by KOH solution is the most common industrial method nowadays. Recently we proposed Nonlinear Laser Lithography (NLL) as an alternative method for the traditional chemical etching [2] . The method is based on the well known phenomenon Laser Induced Periodic Surface Structuring (LIPSS), allowing creation of wellordered, periodic ablation and/or oxidation lines on the material surface with subwavelength period under ultrashort pulse laser illumination. In comparison with the traditional chemical treatment, the method is cheap, single-step and chemically free. However, the damage of the crystalline structure of the SC surface during ablation limiting the final efficiency of the device. In the current work, we demonstrate the new achievement in the efficiency of c-Si solar cell based on NLL treated surface. By proper design of the laser parameters and the scanning geometry during the NLL process, as well as proper post-passivation of the SC surface, we demonstrate more than 16% efficiency of the final device. To the best of our knowledge, this is the highest efficiency demonstrated so far on a laser treated c-Si solar cell without any chemical texturing.