Electrochromic (EC) devices suitable for large area architectural appl
ications require a minimum acceptable performance in depth of color, s
witching time, chromatism and durability to be viable. In this paper w
e discuss these minimum needs and present performance data on various
devices that meet or exceed most of these requirements with neutral co
loration and depth of color > 10:1. These devices have demonstrated re
peatable performance for > 20000 cycles. (C) 1997 Elsevier Science B.V
.