Advantages of photoplating for laser doped solar cells

Abstract

The use of laser doping in solar cell fabrication has received increased attention in recent years, especially due to its ability to form a selective emitter without subjecting the wafer to prolonged high temperature processes and likely corresponding degradation. At the University of New South Wales, a novel laser doping method was developed that combines the formation of the selective emitter with a self-aligned metallisation pattern. This paper investigates the influence of different plating methods on shunt and enhanced recombination regions. It was found that the pseudo fill factors of solar cells plated using photoplating are higher compared to those plated with the electroless method, indicating reduced shunting and/or junction recombination. The superiority of the photoplating method is even more pronounced at high laser powers. According to our knowledge this is the first time photoplating and electroless plating techniques have been compared for laser-doped solar cells.

Review of Ni-Cu Based Front Side Metallization for c-Si Solar Cells

“…(iv) For laser based processing such as laser doping or ablation, LIP can avoid deposition in regions where microcracks are generated since the photovoltage is low [61]. This is unlike electroless plating in which plating takes place on the exposed Si and hence increases the formation of shunts in laser damaged areas.…”

Evolution of metal plating for silicon solar cell metallisation

“…For dry laser‐doping, the concentration of the phosphorus dopant source and spin‐coating conditions as well as the laser parameters can affect the properties of the laser‐doped regions and consequently also the subsequent LIP . Recent reports have demonstrated that both dry and wet approaches can result in heavily‐doped grooves, which can be metallised using LIP nickel/copper/silver or LIP nickel/silver . Because the patterning process also forms the selective‐emitter, metallisation of laser‐doped front surface grids is a self‐aligning process, thus making the technology attractive for manufacturing.…”

“…For dry laser-doping, the concentration of the phosphorus dopant source and spin-coating Silicon solar cell metallisation A. Lennon, Y. Yao and S. Wenham conditions as well as the laser parameters can affect the properties of the laser-doped regions and consequently also the subsequent LIP [64]. Recent reports have demonstrated that both dry and wet approaches can result in heavilydoped grooves, which can be metallised using LIP nickel/ copper/silver or LIP nickel/silver [27,56,57,59,61,62,65].…”

Non-destructive Raman evaluation of a heavily doped surface layer fabricated by laser doping with B-doped Si nanoparticles

“…The carrier concentration of the heavily B-doped surface layer is larger than approximately 10 19 cm À 3 . A laser doping method has been developed for heavily doped surface layers [2][3][4][5][6][7][8]. This technique has some advantages associated with the use of laser light.…”