Selective Emitter Formation via Laser Doping with Picosecond Pulsed Laser for High-Efficiency PERC Solar Cells


Bektaş G.

38th European Photovoltaic Solar Energy Conference and Exhibition, 01 October 2021, pp.271-273

Abstract

In this study, we develop a POCl3 diffusion recipe so that we obtain a thicker phosphosilicate glass layer for laser doping. The formation of a laser doped selective emitter is achieved by utilizing an industrial-type picosecond pulsed laser operating at 532 nm (green) wavelength () and pulse repetition rate (frep) of 1 MHz. To demonstrate the selective emitter concept, sheet resistance reduction of the laser processed region after tube furnace diffusion is provided. In addition, produced samples are metalized and the difference of contact resistivities of both homogenous emitter and laser doped emitter is shown. By applying a moderate amount of heat accumulation on the surface, specific contact resistivity of the laser doped region is reduced to around 3 mΩ.cm2. We report process details and results in this paper.