Tunable chiroptical activity and second-harmonic generation in chiral one-dimensional perovskites

By simply tuning the proportion of lead iodide in the precursor solution, we significantly modulate the intrinsic chiroptical activity of chiral one-dimensional perovskites, yielding a circular dichroism dissymmetry factor of up to 0.11. We further achieve effective second-harmonic generation in the chiral perovskite thin films and observe pronounced second-order nonlinear chiroptical responses.