Controlled investigation of the beneficial effects of aluminum treatment on silicon solar cells was conducted. It was found that Al treatment, which involved /spl sim/1 /spl mu/m Al evaporation followed by a high temperature drive-in, can getter process-induced as well as grown-in defects and impurities by providing a sink. Additionally, forming gas anneal after the Al treatment can generate atomic hydrogen to passivate defects. Al treatment on low resistivity FZ cells gave less than 1% increase in cell efficiency, exclusively due to Al back surface field effect and not because of gettering or passivation. Cast polysilicon cells showed about 1% improvement in absolute cell efficiency, primarily due to the improved diffusion length via Al gettering of defects and contaminants. Finally, the Al treatment resulted in a 5.2% increase in absolute efficiency of EFG cells with 1.7% increase resulting from the Al gettering alone, 2.6% from hydrogen passivation due to the forming gas treatment alone, and 1.2% due to the passivation from the interaction between forming gas and Al.< >
The new deposition process, combustion chemical vapor deposition, shows a great deal of promise in the area of thermal barrier coating systems. This technique produces dense, adherent coatings, and does not require a reaction chamber. Coatings can therefore be applied in the open atmosphere. The process is potentially suitable for producing high quality CVD coatings for use as interlayers between the bond coat and thermal barrier coating, and/or as overlayers, on top of thermal barrier coatings. In this report, the evaluation of alumina and ceria coatings on a nickel-chromium alloy is described.
'%3e%3cpath fill='%23012169' d='M0 0v30h60V0z'/%3e%3cpath stroke='%23fff' stroke-width='6' d='m0 0 60 30m0-30L0 30'/%3e%3cpath stroke='%23C8102E' stroke-width='4' d='m0 0 60 30m0-30L0 30' clip-path='url(%23b)'/%3e%3cpath stroke='%23fff' stroke-width='10' d='M30 0v30M0 15h60'/%3e%3cpath stroke='%23C8102E' stroke-width='6' d='M30 0v30M0 15h60'/%3e%3c/g%3e%3c/svg%3e)