[phrasal verb] 1 : to end a letter or broadcast by signing or declaring your title She signed off Substantial-efficiency white perovskite LED with substantial mild extraction effectiveness can be built through close to-discipline optical coupling.[154] The close to-area optical coupling among blue perovskite diode and purple perovskite nanocrystal was https://neondesign09753.national-wiki.com/671140/5_simple_statements_about_neon_design_explained