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Analysis of lithium transport in electrochromic multilayer films by neutron depth profiling †
Author(s) -
Lamaze G. P.,
ChenMayer H. H.,
Gerouki A.,
Goldner R. B.
Publication year - 2000
Publication title -
surface and interface analysis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.52
H-Index - 90
eISSN - 1096-9918
pISSN - 0142-2421
DOI - 10.1002/1096-9918(200009)29:9<637::aid-sia909>3.0.co;2-2
Subject(s) - electrochromism , lithium (medication) , neutron , chemistry , neutron activation analysis , electrode , detector , analytical chemistry (journal) , optoelectronics , materials science , optics , radiochemistry , nuclear physics , physics , medicine , chromatography , endocrinology
Thin film ‘rocking‐chair’ type cells hold great promise for ‘smart window’ and rechargeable battery applications. Smart windows alter the transmissivity between any two states over the solar spectrum by electrical current modulation, which causes lithium ions to migrate back and forth between the two electrochromic layers. This paper reports measurement of the lithium distribution in each layer and transport between layers by the method of neutron depth profiling (NDP). Samples are irradiated by a beam of ‘cold’ neutrons that induce the 6 Li(n,α) 3 H reaction. Both the intensity and energy of the reaction products— the α‐particles and tritons—are measured by surface barrier detectors. Comparing the emission intensity with that of a known standard leads to quantitative determination of the lithium concentrations. The energy loss of the emitted charged particles due to interactions with the matrix provides a direct measurement of the depth of the originating lithium nucleus. The non‐destructive nature of the NDP technique allows in situ measurements of the lithium concentration under different voltage bias conditions. The data acquisition method and data analysis techniques are explained. Results of the concentration measurements as a function of bias are presented. Possible applications into other lithium multilayers are also discussed. Copyright © 2000 John Wiley & Sons, Ltd.