Quantum—Confined Electron States in Perovskite Quantum Dots

In the framework of the dipole approximation, it is shown that in the perovskites quantum dots (QDs) \({\text{FAPbBr}}_{3 }\) and {en} \({\text{FAPbBr}}_{3}\) interacting with low-intensity light, the oscillator strengths of transitions as well as the dipole moments allowing transitions between one-particle electron quantum-confined states attain values considerably (by two orders of magnitude) exceeding the typical values of the corresponding quantities in semiconductors. It has been established that the maximum values of the cross section optical absorption of perovskite QDs are reached at the resonant frequencies of electron transitions. These quantities achieve giant values. They are by eight orders of the magnitude higher than the values of these quantities in semiconductor single crystals. This makes it possible to use such nanosystems as of strong absorption nanomaterials in a wide range of infrared waves. The obtained results can be used for creating the nano and heterostructures for advanced nanophotonic applications that operate in conditions of weak optical fields in the infrared region.