Fabrication and properties of high efficiency dye-sensitized solar cells (DSSCs) with photon absorption optimization

Abstract

Dye-sensitized solar cells (DSSCs) have attracted much attention because these unconventional solar cells exhibit high performance and have the potential for low-cost production. To achieve higher performances for solar cells based on organic dyes, comparable to those for solar cells based on the color spectrum, the light absorption of organic dyes is required. In a DSSC, the electrodes are surrounded by a thin shell and a dye monolayer for 3 colors of dyes. Based on the optical properties, the large absorption of light can be given in a colorless dye with a wavelength of the most extensive. Combination colors from three-band basic colors, such as red (R), green (G) and blue (B) can create the optimum light absorption. The Incident Photon-to-charge Carrier Efficiency (IPCE) will be high if the absorption spectrum graph of dye color is large too, therefore the Dye-Sensitized Solar Cell (DSSC) will produce photon current (If) or high short-circuit current (Isc). To ensure solid surface coverage, the dye must have a high absorption coefficient on TiO2. The electrodes can be maximized with reduced layer thickness so the possibility of recombination decreases with decreasing electrode thickness and thicker electrolytes with low vapor pressure can be applied. The longer the wavelength, the less absorption will cause a small portion of the sun's spectrum to disappear. The experiment showed that a combination of three band colors of dye is obtained the largest light absorption. This black color proved to have the greatest light absorption. The experiment can result for the exhibit a high open-circuit voltage VOC of 320 mV, open-circuit current IOC of 0.045 mA, maximum voltage Vmax of 134 mV, maximum current Imax of 0.044 mA, maximum power Pmax of 5.89 μW, Fill Factor (FF) of 42 and a power conversion efficiency of 9.1%.