Small Molecule Anchored to Mesoporous ITO for High-Contrast Black Electrochromics

We developed transmissive-to-black electrochromic devices by assembling p -aminotriphenlyamine (pAT) on the surface of mesoporous tin-doped indium oxide (mITO) electrodes. pAT-modified electrodes possess an optical contrast ratio of up to 64%, switching speeds of 1–4 s, and enhanced chemical reversibility as compared to unbound pAT in solution. Gel permeation chromatography (GPC) and inductively coupled plasma mass spectrometry (ICP-MS) were used to analyze the electrochemical degradation products of pAT-modified electrodes and pAT in solution. The rare transparent-to-black electrochromism of pAT makes it a promising small-molecule, anodically coloring material for smart window applications.