Rare-earth ion-doped perovskite quantum dots: synthesis and optoelectronic properties

Rare-earth Nd 3+ ions were doped into CsPbBr 3 perovskite quantum dots (QDs) by solution-processed method at room temperature. By controlling different doping ratios, all-inorganic perovskite QDs with mixed-cations were obtained. The introduction of rare-earth ions into perovskite QDs has little influence on morphology evolution, with cubic shape for all samples. Spectra tuning can be realized by controlling rare-earth ion doping in perovskite QDs. The PL peak was blue-shifted from 515 to 500 nm, while full width at half maximum (FWHM) changes slightly. The results are mainly due to the smaller Nd ion radius than the Pb ion radius, resulting in the decrease of lattice constant and increase of band gap width. The performance of light-emitting diodes (LEDs) based on Nd 3+ -doped CsPbBr 3 QDs have been explored, which indicates inferior activity with extra Nd 3+ doping. The impurities and foreign phase induced by rare-ion doping, may increase halogen vacancies ( V Br ) in the products, which could act as quenching centers, resulting in nonradiative energy transfer to the trap states, and then the inferior performance of perovskite LEDs.