The 16th International Meeting on Electrochromism (IME-16) (IME-16)

Electrochromic displays are promising for wearable and portable applications, yet their fabrication is often limited by costly patterning methods. Here we developed a simple and low-cost direct photolithographic approach to fabricate high-resolution flexible displays using commercial PEDOT:PSS blended with a photosensitive crosslinker, HDDO. Upon UV exposure, HDDO polymerises and crosslinks with PSS, rendering exposed areas insoluble while unexposed regions are washed away, producing patterns with feature sizes below 50 µm. The photo-crosslinked films retain excellent electrochromic performance on flexible ITO-PET substrates. The devices exhibit fast switching (<0.5 s) and outstanding reversibility (>10,000 cycles).  We demonstrate practical reflective-display applications, including a logo, a QR code, and a price tag, all of which operate reliably under low voltages and withstand bending without performance loss. This work offers a straightforward, scalable, and economical route to flexible electrochromic displays, avoiding complex molecular design and expensive equipment, and thus facilitating their commercial adoption in next-generation flexible electronics.