Design of periodic dielectric multilayer thin films for colorizing PV panels

Colored photovoltaic (PV) panels can be aesthetically integrated into buildings, accelerating the transition from energy-consuming to energy-generating buildings. To best balance the architectural aesthetic requirements and the electrical performance of colored PV panels, this study analyses the spectral characteristics and colorizing effects of six typical film stacks. Two optimal stacks that can realize diverse architectural styles are recommended. These two stacks could achieve bright soft or solid dark tonal styles with only 3 to 7 layers. The suggested transmittances of film stacks at the best color performance are 90.3% and 66.9%. After analyzing the chromaticity points of 30 film stacks, this study demonstrates that the narrow-band film stacks have a wider color gamut and more comprehensive colorizing ability than the wide-band film stacks. Moreover, the film stacks from 1 layer to 11 layers are compared. It is found that a 5-layer design is the recommended upper limit for the application of narrowband stacks. The study confirm multilayer thin film stack as an promising solution for colorizing PV panels with a relatively simple fabrication process, realizing a decent compromise between visual appeal and electrical performance.