Ultrafast and Nonlinear Optical Properties of Two-Dimensional Mo-Doped Dual Phase Inorganic Lead Halide Perovskite

Two-dimensional (2D) inorganic halide nanomaterials are finding tremendous attention owing to ease of synthesis, solution processability, superior electronic, optical, and mechanical properties resulting in versatile applications. All inorganic dual phase perovskite composites can have superior optoelectronic properties than a single phase one. In addition to dual phase, doping with various ions may open up new avenues for emerging applications of such materials. In this work, we report on the synthesis of colloidal 2D Mo-doped all inorganic dual phase mix halide perovskite (CsPbBr3/CsPb2Br5). The charge carrier dynamics in these nanostructures has been studied with femtosecond transient absorption technique. Our studies reveal that at low pump fluences cold carrier trapping predominantly affects relaxation dynamics at early time. However, Auger recombination of excitons dominates the early time carrier relaxation at high fluences. Additionally, femtosecond Z-scan studies have been performed to elucidate the effect of photoinduced charge carriers on two photon absorption (TPA) properties of Mo-doped 2D perovskite. Our results could be useful for designing new low-dimensional perovskites for future linear and nonlinear optoelectronic applications.

Automated summary

Two-dimensional inorganic halide nanomaterials have attracted tremendous attention due to their simple synthesis, solution processability, superior electronic, optical, and mechanical properties, as well as versatile applications. Inorganic dual phase perovskite composites may exhibit superior optoelectronic properties compared to single phase materials, and doping with various ions can lead to emerging applications. In this study, we report the synthesis of colloidal 2D Mo-doped all inorganic dual phase mixed halide perovskite and investigate the charge carrier dynamics using femtosecond transient absorption technique. Our results reveal that carrier trapping and Auger recombination dominate the carrier relaxation at different energy densities. Additionally, femtosecond Z-scan studies elucidate the effect of photoinduced charge carriers on two photon absorption properties. These findings can contribute to the design of new low-dimensional perovskites for future optoelectronic applications.