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.
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.