Sensitizer molecular structure-device efficiency relationship in dye sensitized solar cells

Abstract

In the Dye Sensitized Solar Cell (DSSC) the dye sensitizer carries out the light harvesting function and is therefore crucial in determining overall cell efficiency. In addition, the dye sensitizer can influence many of the key electron transfer processes occurring at the TiO(2)/dye/electrolyte interface which also determine efficiency. Dye structure can influence and drive forward electron injection into the conduction band of the TiO(2). Conversely, dye structure can help retard loss electron transfer processes such as charge recombination of injected electrons in the TiO(2) with dye cations and also recombination of these electrons with the electrolyte. Therefore tuning dye sensitizer light absorbing properties and control of the aforementioned electron transfer processes through structural design of the dye sensitizer is an important avenue through which optimization of DSSC efficiency should be pursued. In this critical review the latest work focusing on the design of dyes for efficient DSSCs is revised (111 references).

Charge recombination losses in thiophene-substituted porphyrin dye-sensitized solar cells

“…In this type of solar cell the properties of the dye, such as colour, molecular extinction coeffi-cient and robustness under illumination, are of utmost importance. Among the examples of dyes published in the literature [3] for Gratzel€ solar cells, porphyrins [4] have pleasant colours [5], excel-lent molecular extinction coefficients [6,7] and good robustness [8,9]. Moreover, based on the work of Yella and co-workers [1], efficiencies that surpass the values obtained with ruthenium sen-sitizers have been achieved.…”

Enhanced Photovoltaic Performance via Co-sensitization of Ruthenium (II)-Based Complex Sensitizers with Metal-Free Indoline Dye in Dye-Sensitized Solar Cells

“…Photosensitizers work as solar light harvesters of Photovoltaic (PV) cells. In addition their electronic properties are recognized to affect light harvesting efficiency along with power conversion efficiency (PCE) [9,10]. In DSSCs, the majority of low efficiencies are based on traditional photosensitizers undergoing low absorption, narrow absorption spectra, along with the loss of energy absorbed by the electrolyte [5].…”

“…Rutheniumbased sensitizers such as the N3 dye/ N719 dye [9,10,23] and black dye [24] were rigorously tested as light har-vesters and reached remarkable overall power conversion efficiency (η) in the range of 11% under Air Mass 1.5 (AM 1.5) irradiation while organic photosensitizers have reached power conversion efficiency (PCE) in the range of 5-8% [25][26][27][28][29][30][31]. Metal-free indoline dye (D149) is the most effective photosensitizer for DSSCs and has attained very high efficiencies of 9% [32].…”

Design and synthesis of organic sensitizers with enhanced anchoring stability in dye-sensitized solar cells

“…To develop high-performance DSSCs, it is important to optimize all their components (sensitizer, nanocrystalline semiconductor, electrolyte, and counter electrode) in order to improve both efficiency and stability of the device. Nevertheless, a special attention needs to be dedicated to the optimization of photosensitizers, as the latter are directly involved in the light-harvesting and charge-separation processes [8], and are therefore largely responsible for cell performances.…”