Room-temperature up-conversion random lasing from CsPbBr₃ quantum dots with TiO₂ nanotubes

We report successful room-temperature up-conversion random lasing by distributing CsPbBr₃ quantum dots (QDs) uniformly into TiO₂ nanotubes (NTs). In order to overcome the difficulty in purifying the QDs, TiO₂ NTs were designed to collect QDs and enhance the optical multiple scattering effect. A threshold of 9.54  mJ/cm² and narrow full width at half-maximum of 0.49 nm with a relatively high quality factor of 1089 were successfully observed. These results indicate that CsPbBr₃QDs/TiO₂ NTs can be high-performance up-conversion lasers for practical applications, especially when the phase matching required by conventional approaches cannot be fulfilled.