Researchers are exploring the potential of lanthanide-doped upconversion nanoparticles in various applications, including optoelectronics, theranostics, and antibacterial treatments. These nanoparticles are being combined with other materials, such as perovskite nanocrystals, to create multifunctional nanocomposites with advanced properties. The resulting materials are being investigated for uses such as information storage, biomarker detection, and photodynamic therapy.