A comparative study on electrical properties of dye-sensitized solar cell and silicon photodiode under colored light for optical sensor applications

In order to investigate the feasibility of applying dye-sensitized solar cells (DSSC) as optical sensors, DSSC and Si photodiode (Si PD) were irradiated by RGB LED with various colors and intensities, and the electrical properties were recorded. The relationships between the electrical properties, color and intensity of light are contrastively analyzed. The open-circuit voltage (Voc) of DSSC is larger and much more stable with the variation of light intensity than that of Si PD, while the short-circuit current (Isc) of DSSC is relatively smaller than that of Si PD. The colored light is assumed to be monochromatic light with similar color by using conversion algorithm written by Dan Bruton. High relative deviation between the experimental intensity and the calculated incident intensity is found in DSSC and Si PD, confirming the exoterica that RGB-mixed light is not monochromatic in nature though their color is similar. Isc and Voc response time under pulsed irradiation by RGB light were studied, and the results show that Isc rise time of DSSC is ∼150 ms, which is at least three times as long as that of Si PD, and Voc fall time of DSSC is much longer than that of Si PD.