Claes-Goran Granqvist1

1, The Ångström Laboratory, Uppsala University, Uppsala, , Sweden

This paper outlines the essential properties of the the radiation around us, and uses this information to specify a number of requirements for energy efficient glazing. Spectral selectivity, angular dependence, and time variability stand out as important concepts. Focus is then put on novel results for thermochromic and electrochromic materials and devices. In particular, I present a number of strategies for boosting the cycling stability of electrochromic thin films of tungsten oxide and nickel oxide by electrochemical pretreatment or post treatment in lithium-ion-conducting electrolytes, or by intermixing of several oxides.