Product Code: ICAL09_P116

High Speed Laser Micro-Texturing of Si Wafer for Improved Light Trapping for Photo-Voltaic Application
Authors:
Ana Pena, The University of Manchester; Manchester Great Britain
Zengbo Wang, The University of Manchester; Manchester Great Britain
David Whitehead, The University of Manchester; Manchester Great Britain
Lin Li, The University of Manchester; Manchester Great Britain
Presented at ICALEO 2009

The demand for efficient, alternative sources of energy is a growing and crucial issue in todays world. Solar energy offers a vast, inexhaustible, free and clean option for future power needs. Although new technologies emerge every day, silicon-based solar panels represent the most feasible and commercial solution. The reason for this is its well established manufacturing process and the abundance of this material in the earths crust. In order to achieve highly efficient devices, all losses associated with the photovoltaic cell operation must be minimized. Amongst them, optical losses as high as 30% light reflectivity are characteristic of bare Si substrates. In this paper reduced reflectivity is reported by micro-texturing the front surface of a crystalline silicon wafer using a diode pumped Nd:YVO4 laser system with a computer controlled 3 axis galvanometer beam scanner. High laser scanning speeds (> 1 m/s) were applied so this texturing technique might compete with current industrial texturing practices. Additionally, wetting characteristics of the processed areas are investigated aiming to achieve self-cleaning solar panels.