In situ measurement of lithium movement in thin film electrochromic coatings using cold neutron depth profiling

✍ Scribed by Lamaze, G. P.; Chen-Mayer, H.; Badding, M.; Laby, L.

• Publisher: John Wiley and Sons
• Year: 1999
• Tongue: English
• Weight: 135 KB
• Volume: 27
• Category: Article
• ISSN: 0142-2421
• DOI: 10.1002/(sici)1096-9918(199907)27:7<644::aid-sia554>3.0.co;2-4

✦ Synopsis

Direct analysis of lithium movement within multilayer thin-Ðlm electrochromic (EC) coatings has been performed by cold neutron depth proÐling (CNDP). Transfer of lithium between a counter-electrode layer and an EC tungsten trioxide layer controls the optical density of the EC coating. The lithium proÐles have been measured using the CNDP instrument at the Center for Neutron Research at the National Institute of Standards and Technology. The lithium depth proÐles are based on measurement of the energy of alpha particles from the 6Li(n,a)3H reaction. The alpha particles lose energy as they exit the Ðlm and this energy loss provides direct measurement of the depth of the originating lithium nucleus. In this case, in situ measurements were taken with di †erent bias voltages on the Ðlm layers. The bias causes the lithium to migrate between di †erent layers, changing the optical density of the Ðlms. A great advantage of the CNDP technique is that it is non-destructive, which allows repeated observation of the lithium movement. Results of simultaneous optical transmission measurements and lithium proÐle measurements are reported.