Investigation of nanoporous silicon on the frontal surface of solar cells by mass spectroscopy

Abstract

When using nanoporous silicon (nano-PSi) as a texture and anti-reflective coating, the nanoporous layer is formed directly on the silicon surface of the front layer of solar cells (SC). Along with blooming, it must also provide passivation of the SC surface. Research in this area has shown that the passivating properties of PSi are insufficient to minimize surface recombination. Partial improvement of the passivating properties of nano-PSi was achieved by thermal and anodic oxidation, as well as by plasma spraying methods. However, none of these methods were allowed to achieve the required level of surface passivation and its stabilization over time. A more effective method of improving the passivating properties of PSi is electrochemical hydrogenation in hydrogen-enriched electrolytes. Here we used mass spectroscopy to study the frontal surface of the SC. We also studied the surface appearance of multicrystalline silicon samples before and after hydrogenation in hydrogen and in an electrolyte based on hydrofluoric acid, both in the spectra of secondary ions and in the image of the distribution of elements on the surface.