Department of Engineering Sciences Solid State Physics
Uppsala University, SE



Dr. Bayrak Pehlivan is researcher at the Department of Engineering Sciences, Uppsala University (Sweden). She received her BSc in Physics at İstanbul University (2002). Her MSc study was on dielectric spectroscopy of free radical polymerization of polyvinylpyrrolidone, conducted at Physics Engineering, İstanbul Technical University (2005). She graduated with the PhD degree from Uppsala University in Engineering Science. Her thesis was a study of the functionalization of polymer electrolytes for electrochromic windows (2013). She was awarded the Ångström Materials Academy Innovation Prize on the basis of a part of her PhD study on electrochromic devices with nanoparticle added-polymer electrolytes. Previously, she worked as development engineer at ChromoGenics AB, which offers dynamic glass with controllable heat- and light transmission in Sweden (2013-2015). Since the end of her parental leave (2016), she continues her research on solar water splitting systems, including simulations for integrated solar water splitting systems, and develops electrocatalysts as well as electrochromic materials.​​

​Presentation ​

Electrochromic Device Technology​

Electrochromism (EC) is a promising energy-saving technology that makes it possible to control the transmission of solar energy and visible light through a device. It is employed in several new technologies, such as in “smart windows” which are able to provide energy efficiency and indoor comfort and are currently used in modern buildings. The EC technology can be implemented in different ways, for example by web-coating where the active materials can be delivered on foils as a roll, or in the form of large sheets for glass lamination. Today’s smart windows typically include thin films based on tungsten oxide and nickel oxide separated by a solid inorganic thin-film ion conductor, or a layer of polymer electrolyte. Transmittance modulation is accomplished when a voltage is applied between the tungsten oxide and nickel oxide thin films, via transparent electrical conductors, so that ions and charge-balancing electrons are shuttled between the two films. In this talk we will present results covering: (i) pre-treatment and post-treatment methods pioneered by the Uppsala group to enhance electrochromic properties, (ii) progress regarding durability under electrochemical cycling of mixed oxide EC thin films, (iii) enhanced electrochromic properties with nitrogen doped EC films, (iv) a new experimental method, which was recently developed at Uppsala University, for simultaneously studying both the dynamic electrical and optical response of electrochromic materials using a combination of electrochemical impedance spectroscopy and color impedance spectroscopy, and (v) possibilities to combine electrochromism with other applications such as thermochromic control of solar energy transmittance and solar water splitting. ​​​​