Fast-Switching Vis-IR Electrochromic Covalent Organic Frameworks

Electrochromic coatings are promising for applications in smart windows or energy-efficient optical displays. However, classical inorganic electrochromic materials such as WO3 suffer from low coloration efficiency and slow switching speed. We have developed highly efficient and fast-switching electrochromic thin films based on fully organic, porous covalent organic frameworks (COFs). The low band gap COFs have strong vis-NIR absorption bands in the neutral state, which shift significantly upon electrochemical oxidation. Fully reversible absorption changes by close to 3 OD can be triggered at low operating voltages and low charge per unit area. Our champion material reaches an electrochromic coloration efficiency of 858 cm2 C-1 at 880 nm and retains >95% of its electrochromic response over 100 oxidation/reduction cycles. Furthermore, the electrochromic switching is extremely fast with response times below 0.4 s for the oxidation and around 0.2 s for the reduction, outperforming previous COFs by at least an order of magnitude and rendering these materials some of the fastest-switching frameworks to date. This combination of high coloration efficiency and very fast switching reveals intriguing opportunities for applications of porous organic electrochromic materials.

Medienart:

E-Artikel

Erscheinungsjahr:

2021

Erschienen:

2021

Enthalten in:

Zur Gesamtaufnahme - volume:143

Enthalten in:

Journal of the American Chemical Society - 143(2021), 19 vom: 19. Mai, Seite 7351-7357

Sprache:

Englisch

Beteiligte Personen:

Bessinger, Derya [VerfasserIn]
Muggli, Katharina [VerfasserIn]
Beetz, Michael [VerfasserIn]
Auras, Florian [VerfasserIn]
Bein, Thomas [VerfasserIn]

Links:

Volltext

Themen:

Journal Article

Anmerkungen:

Date Revised 28.05.2021

published: Print-Electronic

Citation Status PubMed-not-MEDLINE

doi:

10.1021/jacs.0c12392

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM322814391