Cold field emission electrode as a local probe of proximal microscopes: Investigation of defects in monocrystalline silicon solar cells

• Published in: World journal of engineering 2013-06, Vol.10 (2), p.119-124
• Main Authors: Tománek, P., Škarvada, P., Dallaeva, D., Grmela, L., Macků, R., Smith, S.
• Format: Article
• Language: English
• Subjects: Crystal defects; Crystal structure; Electrical noise; Electrodes; Emission analysis; Field emission; Irregularities; Near field optical microscopes; Optical microscopes; Photovoltaic cells; Silicon; Solar cells
• ISSN: 1708-5284
• DOI: 10.1260/1708-5284.10.2.119

Monocrystalline silicon is still very interesting material for solar cells fabrication due to its quality and external efficiency. Nevertheless during a tailoring of eligible silicon wafers, some inhomogeneities or irregularities emerge and provide defects which give trouble to good operation of solar panels. Generally, there are two classes of defects in silicon wafer: material defects due to imperfections or irregularity in crystal structure (point, line, square or volume defects), and defects induced by wafer processing. To avoid a use of damaged cells, macroscopic and microscopic measurement techniques must be applied. In this paper we present a microscopic method combining electrical noise measurements with scanning probe localization of luminous micro-spots defects. The paper brings experimental results showing local electric and optical investigations of defects in etched monocrystalline silicon solar cells and a use of cold field emission tungsten electrode as a local probe for apertureless scanning near-field optical microscope.