The Definition of Electrochromism

Many experimental studies of electrochromism have been reported in the scientific literature, but the terminology is still not settled, particularly for the case in which an electrochromic material forms the load in an electrical circuit. In the present work, two new terms are introduced to help clarify this situation. These terms are dielectric electrochromism and faradaic electrochromism. The first term applies to the case where an applied electric current causes a change in the energy of the electronic states in the material, while the second term applies to the case where an applied electric current causes a change in the occupation number of the electronic states in the material. Precise definitions are given of both terms.