Analysis of chromogenic materials for angular-selective smart windows with efficient use of solar energy

Abstract

This paper analyzes the achievements in recent years in the development of chromogenic materials and technologies, with a special emphasis on those that would be most effective for use both in conventional smart windows with a single continuous chromogenic layer, developed since the 1990s, and in grating smart windows, the development of which began in the 2010s. The latter have some advantages in creating a comfortable indoor lighting environment, such as angle-selective limitation of the transmission of direct solar radiation while increasing the transmission of sky-scattered radiation and radiation reflected from the ground and the facades of opposing buildings. The angular selectivity of a grating smart window is ensured by alternately passing direct sunlight through thin-film gratings with alternating transmissive and chromogenic strips on two window surfaces. Among the variety of chromogenic technologies, the most promising ones for smart windows of both types were identified. Taking into account the technological features of manufacturing grating windows, the possible cost of this technology was preliminary estimated.