Controllable synthesis of CsPbI nanorods with tunable photoluminescence emission.

So far the controllable synthesis of one-dimensional (1D) CsPbI nanocrystals still remains a challenge due to the fast reaction kinetics of the iodine system as compared with other halide perovskites. Here we report the direct synthesis of high-quality 1D CsPbI nanorods by a facile solvothermal method. The as-prepared CsPbI nanorods show high purity and uniform morphology with ultrafine diameters down to ∼5 nm. By simply changing the solvothermal reaction conditions, fine-tuning of the sizes of the CsPbI nanorods can be well achieved, which leads to the successful modulation of their photoluminescence (PL) emission. The solvothermal reaction offers relatively low crystal growth rate, which is of great importance for the size control of the CsPbI nanocrystals. PL quantum yields (PLQYs) and lifetime results indicate that the obtained nanorods maintain a good surface state over long reaction time. Our work not only provides a reliable means for the synthesis of 1D iodine-related perovskites, but also expands the study of size-related PL properties on perovskites nanocrystals.