Abstract
A system consisting of three dye-sensitized solar cells (DSSCs), each tailored with a light absorption maximum in short, medium or long wavelengths was developed for color sensing purposes using anthocyanins from red cabbages. Anthocyanins absorb light in the UV-Vis region and have pH-dependant light absorptivity profiles that were easily adjusted to suit this purpose. The system is constructed with inspiration from the three specialized photoreceptors in the human visual system, and quantum efficiency (QE) values of the system are analyzed in ways that mimic the data-processing methods of human vision, which are explained by both the trichromatic and opponent-process color theory. A successful method of using the quantum efficiency (QE) of the tri-DSSC system to interpret the color of the incident light (wavelength) was thus proposed. When six monochromatic incident light sources were used to characterize the response of the tri-DSSC system, the opponent color theory-based analysis method, which compares the sum and differences of the tri-DSSC QE values, returned more accurate color results by providing highly distinguishable values for each wavelength while the method of using QE ratio comparison alone returned more ambiguous results in multiple wavelength ranges. To use the tri-DSSC system to identify colors at different irradiances, corrections must be made to QE values assuming a linear relationship between QE and irradiance, or new QE values need to be measured directly. In conclusion, the tri-DSSC system has proven its potential in recognizing colors at a uniform incident irradiance level and the possibility to improve its color sensing functions are promising as multiple strategies to improve its future designs are available.