Chemical Processing of Cu₂SnS₃ Nanoparticles for Solar Cells

The growing energy crisis has attracted global attention as conventional nonrenewable energy resources are on the route to depletion. Moreover, the soaring prices and their detrimental effects on the environment, such as pollution and global warming, have led to finding alternative energy sources. The solar industry has received great attention due to its potential capability to satisfy growing energy demands. Accordingly, diverse chalcogenide-based photo absorber materials such as CdTe, CuInSe, CuInGaS (CIGS), and Cu₂ZnSnS₄ (CZTS) have been employed for solar cell fabrication. However, due to its multielement nature, structural complexity, element scarcity, and toxicity have stagnated their future usage in photovoltaic (PV) applications. The Cu₂SnS₃ (CTS), a ternary semiconductor compound comprised of nontoxic and earth-abundant elements, is considered an emerging photo absorber material as it exhibits suitable structural and optical properties. Generally, to fabricate CTS absorber material, chemical routes are widely preferred over conventional physical routes due to their simplicity, cheaper, and low wastage of material. These chemical methods include chemical bath deposition, hot injection, one-pot chemical synthesis, and microwave irradiation. Further, the nanoparticles (NPs) prepared by chemical methods with various size-shape, chemical compositions, and phases can be coated on a substrate to produce a high-quality photo absorber layer for solar cell application. This chapter mainly covers the chemical processing of CTS NPs and their nano-ink formulation for solar cell application. In addition, it carries a brief overview of chemical methods for solution processing of CTS NPs.