Soft organic materials that change color and charge transfer with the application of an electric field

A group of researchers from the Institute of Materials Science of Barcelona (ICMAB-CSIC) led by Prof. Jaume Veciana has proven the ability of an organic molecular metal [(BEDO-TTF)_2,4I₃] to reversibly change its color (electrochromic properties) and its degree of charge transfer (rectifying properties) upon the application of an electric field and have explained its mechanism. With the application of a voltage, some iodine species migrate to the positive regions and the material is chemically transformed, changing its color and the electrical properties, from metallic to semiconductor, forming a diode-type device. This is a reversible process: when the voltage is removed, the original properties come back.

The reported results, published in the Flexible Electronics journal, constitute a proof-of-concept that opens up new possibilities for the design and fabrication of organic electrochromic and rectifying devices that operate with a very simple working principle. Furthermore, the basic requirement for achieving such electrochromic behavior is attained without the need of using a complicated pre-processing or post-processing. This technology provides some advantages over the existing ones: low cost, flexibility, easy working principle, reliability and lower power consumption. All of these could help towards their implementation in real life applications.

Reference Article:

2D organic molecular metallic soft material derived from BEDO-TTF with electrochromic and rectifying properties. Daniel Suarez, Eden Steven, Elena Laukhina, Andres Gomez, Anna Crespi, Narcis Mestres, Concepció Rovira, Eun Sang Choi, and Jaume Veciana. Flexible Electronics. (2018) 2:29; doi:10.1038/s41528-018-0041-1.

More information:

• Press release by ICMAB (English, Spanish, Catalan)
• Press release by CSIC (Spanish)
• News on CSIC websiteNews on CSIC website