Advancing Silver Bismuth Sulfide Quantum Dots for Practical Solar Cell Applications

Colloidal quantum dots (CQDs) show unique properties that distinguish them from their bulk form, the so-called quantum confinement effects. This feature manifests in tunable size-dependent band gaps and discrete energy levels, resulting in distinct optical and electronic properties. The investigation direction of colloidal quantum dots (CQDs) materials has started switching from high-performing materials based on Pb and Cd, which raise concerns regarding their toxicity, to more environmentally friendly compounds, such as AgBiS₂. After the first breakthrough in solar cell application in 2016, the development of AgBiS₂ QDs has been relatively slow, and many of the fundamental physical and chemical properties of this material are still unknown. Investigating the growth of AgBiS₂ QDs is essential to understanding the fundamental properties that can improve this material's performance. This review comprehensively summarizes the synthesis strategies, ligand choice, and solar cell fabrication of AgBiS₂ QDs. The development of PbS QDs is also highlighted as the foundation for improving the quality and performance of AgBiS₂ QD. Furthermore, we prospectively discuss the future direction of AgBiS₂ QD and its use for solar cell applications.