Enhancing Förster Resonance Energy-Transfer Rates in Perovskite Quantum Dots via Controlling Donor–Acceptor Ratios

Perovskite quantum dot (QD) semiconductor materials are attractive candidates for various optoelectronic applications due to their unique optical properties. Incorporating nonradiative mechanisms of Förster resonance energy transfer (FRET) could enhance device efficiency by enabling a high-rate FRET process. In perovskite QDs of two-size mixtures, we observed a decreased donor photoluminescence (PL) lifetime and an enhanced acceptor PL lifetime, demonstrating the occurrence of the FRET process. Femtosecond transient absorption spectra show rapid picosecond lifetimes of the FRET process in the QD material-based system. By increasing the acceptor/donor ratio, the process is highly efficient ( E FRET = 81.8%) and extremely fast ( k FRET = 102.0 ns –1 ) with only a short distance between adjacent QDs. The results pave the way for the development of highly defined cascaded energy-transfer structures to achieve efficient energy harvesting.