Electrochemical pixel device

A pixel device, which comprises the following components:

• (A) an electrochemical transistor device comprising:
• a source contact;
• a drain contact;
• at least one gate electrode;
• an electrochemically active element arranged between, and in direct electrical contact with, the source and drain contacts, which electrochemically active element comprises a transistor channel and is of a material comprising an organic material having the ability of electrochemically altering its conductivity through change of redox state thereof;
• and a solidified electrolyte in direct electrical contact with the electrochemically active element and said at least one gate electrode and interposed between them in such a way that electron flow between the electrochemically active element and said gate electrode(s) is prevented;
• whereby flow of electrons between source contact and drain contact is controllable by means of a voltage applied to said gate electrodes), and
• (B) an electrochromic device comprising:
• at least one electrochromic element comprising (i) at least one material that is electrically conducting in at least one oxidation state and (ii) at least one electrochromic material, wherein said materials (i) and (ii) can be the same or different;
• at least one layer of a solidified electrolyte which is in direct electrical contact with said electrochromic element;
• and at least two electrodes adapted for application of a voltage therebetween;
• each of said electrodes being in direct electrical contact with a component selected from said electrolyte layer(s) and said electrochromic element;
• in which pixel device one of said source and drain contacts of the electrochemical transistor device A is in electrical contact with one of the electrodes of the electrochromic device B.