Controlled size growth of thermally stable organometallic halide perovskite microrods: Synergistic effect of dual-doping, lattice strain engineering, antisolvent crystallization, and band gap tuning properties

Abstract

Organometallic halide perovskites, as the light-harvesting material, have been extensively used for cost-effective energy production in high-performance perovskite solar cells, despite their poor stability in the ambient atmosphere. In this work, methylammonium lead iodide, CH3NH3PbI3, perovskite was successfully doped with KMnO4 using antisolvent crystallization to develop micrometer-length perovskite microrods. Thus, the obtained KMnO4-doped perovskite microrods have exhibited sharp, narrow, and red-shifted photoluminescence band, as well as high lattice strain with improved thermal stability compared to undoped CH3NH3PbI3. During the synthesis of the KMnO4-doped perovskite microrods, a low boiling point solvent, anhydrous chloroform, was employed as an antisolvent to facilitate the emergence of controlled-size perovskite microrods. The as-synthesized KMnO4-doped perovskite microrods retained the pristine perovskite crystalline phases and lowered energy band gap (∼1.57 eV) because of improved light absorption and narrow fluorescence emission bands (fwhm < 10 nm) with improved lattice strain (∼4.42 × 10-5), Goldsmith tolerance factor (∼0.89), and high dislocation density (∼5.82 × 10-4), as estimated by Williamson-Hall plots. Thus, the obtained results might enhance the optical properties with reduced energy band gap and high thermal stability of doped-perovskite nanomaterials in ambient air for diverse optoelectronic applications. This study paves the way for new insights into chemical doping and interaction possibilities in methylamine-based perovskite materials with various metal dopants for further applications.