The phase-controllable crystallization induced by low pressure flashing in chloride anion doped quasi-2D hybrid perovskite thin films for blue light-emitting diodes

ABSTRACT Controlling perovskite phase composition plays an important role in improving the quality of quasi-2D blue emissive perovskite thin films to realize spectrally stability of perovskite LED (PeLED). Herein, the high quality quasi-2D perovskite thin films were prepared by low pressure flashing induce crystallization (LPFC) method, which promoted surface coverage of perovskites to control the removal speed of solvent mixtures unanimously by adjusting the pressure of post-treatment from 1 KPa to 101 KPa. Compared to the common post-treatment method, perovskite thin films produced different quasi-2D phase under the pressure of 20 KPa by LPFC method and corresponding devices possessed high luminance with spectrally stability. Furthermore, the facile LPFC method promoted the volatile speed of high boiling point single solvent and accelerate the crystallization process to realize high quality of quasi-2D perovskite thin films prepared at room temperature.