Smart windows based on photo-responsive LC system doped with photoswitches: Photoisomerization of photoswitches leads to the phase transition of the LC system because of the change of the LC orientation. As a result, smart windows based on the photo-responsive LC system appear in different optical states at various LC phases. Here, we review the working principles and applications of smart windows based on photo-responsive LCs featuring phase transition.

Abstract

A smart window is an optical dimming device with intelligent functions that can control its relevant performances through external stimuli, achieving functions such as privacy protection and temperature regulation. Light is an ideal stimulus for regulating smart windows, which is noninvasive and allows self-adaptable manipulation of materials. This review highlights recent significant achievements in smart windows constructed by photo-responsive liquid crystals (LCs) systems that can undergo the transition between different phases. The smart windows based on photo-responsive LCs are used in a plethora of areas, including privacy protection, absorption glass, building decoration, energy saving, and climate modulation applications. The review concludes with a brief perspective on some significant challenges and opportunities for the future development of photo-responsive smart windows, which is crucial for expanding the applications of smart windows and improving their performances.