Influence of Concentration of Phosphorous Dopant Liquid and Pulse Distance on Parameters of LCP Selective Emitters for Silicon Solar Cells

In this paper newest results concerning n-type Laser Chemical Processing (LCP) doping for varying laser and liquid parameters will be presented with regard to sheet resistance, contact resistance and cell efficiency. In the first part of the paper the influence of dopant concentration reduction is investigated by using a TLM structure. Additionally the pulse energies are varied for different pulse distances to find optimum doping parameters. It is demonstrated that the dopant concentration of the dopant source can be strongly reduced and that for all tested pulse energies an optimal pulse distance exists. To verify if these results are suitable for solar cell production selected laser parameters were tested on a 30×60 mm² screen-printed solar cell structure. An efficiency improvement of 0.4 %abs is achieved for cells with LCP selective emitter in comparison to reference cells without selective emitter under the metal fingers.