Potassium hexafluorogermanate (K₂GeF₆) is an inorganic salt characterized by its white crystalline powder form. It is a key precursor material in the synthesis of germanium-containing compounds and advanced materials. Its primary industrial significance lies in its role as a source of germanium ions. The most prominent application of K₂GeF₆ is in the field of perovskite solar cells (PSCs). It is widely used as a precursor for the preparation of germanium-doped or germanium-based perovskite absorber layers, such as CsGeI₃. Doping with germanium, introduced via K₂GeF₆, can enhance the stability, optoelectronic properties, and power conversion efficiency of the perovskite films. Beyond photovoltaics, it serves as a catalyst precursor in specific organic synthesis reactions and is utilized in the production of special optical glasses and phosphors. This compound is generally stable under recommended storage conditions but requires careful handling due to its potential to release toxic hydrogen fluoride (HF) upon decomposition or reaction with strong acids. Its use is predominantly driven by research and development in next-generation energy materials.