PROCESS OF TEXTURING SILICON SURFACE FOR OPTIMAL SUNLIGHT CAPTURE IN SOLAR CELLS

摘要

A process of treating a silicon substrate surface for optimizing sunlight capture in the fabrication of solar cells is disclosed. Each of the two sides of the silicon substrate is textured with a laser source to roughen its surface by fabricating nanoscale structures thereon. Surface texturing may be conducted on both sides of a crystalline silicon wafer by flipping over to repeat our process on the other side such that sunhght reflectivity is minimized and photon trapping is maximized. The process may be conducted in room temperature and vacuum in a dry-etch processing environment. The substrate may undergo translation in the X- Y axes for control of the substrate's movement to achieve the requisite texturing by the laser beam of a pulse laser of Nd-YAG source in 533 nm and 1024 nm wavelengths at 75 joules/pulse with translation speed of 0.5 mm/second. Our process is suitable for solar cells that includes heteroj unction structures, specifically, with intrinsic thin layer (HIT) structure and particularly on crystalline silicon (c-Si) (p-type) substrate which may include exposure to nano-second to femto-second range pulsed laser on dry thin film solar cell wafer.