Ternary Ag₃AuS₂ Nanocrystals for Thin-Film Solar Cells

The concept of clean and pollution-free energy development has promoted the rise of environmentally friendly silver-based chalcogenide nanocrystal (NC) solar cells, but currently reported silver-based NCs need complex synthesis processes at high temperatures that may bring zerovalent noble metal impurities for their high redox potentials. In this study, we report a facile synthesis of novel Ag₃AuS₂ NCs by injecting highly active oleylamine sulfur complexes as sulfur sources into metal precursor solutions at low temperatures of 60 °C. The obtained Ag₃AuS₂ NCs exhibit broad absorption spectra and high molar extinction coefficients (10⁶ M^-1 cm^-1). Then, the Ag₃AuS₂ NCs are applied as the light-absorbing active layer in environmentally friendly thin-film solar cells. By introducing a hybrid mixture of charge acceptors and donors (NCs/P3HT hybrid film) at the interface, the device gains an absorption increment and enhanced charge extraction, achieving a final power conversion efficiency of 3.38%. This work demonstrates the enormous potential of Ag₃AuS₂ NCs from low-temperature preparation for photovoltaic applications.