DEVELOPMENT OF RUTHENIUM-FREE ORGANOELEMENTAL DYES FOR HIGH-EFFICIENCY DYE-SENSITIZED SOLAR CELLS UTILIZING AZERBAIJANI CLAY MINERAL-TIO₂ COMPOSITE PHOTOANODES

Abstract

Introduction: To overcome the drawbacks caused by the high price and limited availability of conventional Ru(II)-based sensitizer, such as N-3 and N719, and to achieve the commercial possibility for dye-sensitized solar cells (DSSCs), the development of new sensitizers is of great significance. In this paper, we explore an energy-efficient and high-performance new architecture. Goals and objectives: The overall goal is to develop an innovative DSSC architecture by synergistically combining high-efficiency, ruthenium-free, organoelemental dyes with nanostructured composite photoanodes. The aim is to establish a route to low-cost, high-performance photovoltaics by making use of readily available, abundant clay minerals in Azerbaijan as key photoanode constituent. Methods: The approach adopted involves preparation of new composite photoanodes based on titanium dioxide (TiO₂) mixed with locally sourced clay minerals (bentonite and kaolinite). The preparation methods of the clay-TiO₂ composites and their photoanode film fabrication are described. The chapter combines a critical overview of the main active classes of metal-free dyes—porphyrins, phthalocyanines, and indolines—to couple with these novel anodes. Results and Discussion: The combination of Azerbaijani clay minerals to the TiO₂ photoanode will bring in significant benefits to the device performance through different synergistic actions. These factors are (1) the higher specific surface area favoring an enhanced dye loading and light harvesting efficiency, (2) the incorporation of light-scattering centers resulting in a prolonged optical path length across the photoanode; and (3) significantly, the prevention of charge recombination at the photoanode/electrolyte interface by surface passivation. Based on physicochemical studies, it is argued that these effects will contribute to a marked enhancement in the crucial photovoltaic (J_sc/V_oc) parameters, resulting in an overall improvement in the PCE of the device. Conclusions: The combination of advanced organic dyes and novel clay-composite photoanodes proposed in this study is a very attractive practical method to develop cost-effective, environmentally friendly photovoltaic technology. The work has demonstrated a promising theoretical and practical approach for experimenting and optimizing a next-generation high-performance sustainable DSSC, with local natural resources to meet a global energy challenge.