Resonant Second Harmonic Generation in Proline Hybrid Lead Halide Perovskites

Chiral hybrid organic-inorganic perovskites (HOIPs) with intrinsic noncentrosymmetry have shown great potentials for chiroptoelectronic applications including second-order nonlinear optics (NLO). Ideal NLO materials should simultaneously feature a large NLO coefficient, wide optical transparency, high laser damage threshold, and physicochemical stability. However, the development of applicable second-order NLO materials has been largely restricted due to their strict requirement on structural noncentrosymmetry. Here, chiral amino acids abundant in nature have been adopted to synthesize hybrid lead halide perovskites (D-/L-Pro)PbI3 center dot H2O (Pro = Proline) with resonance enhanced second-harmonic generation (SHG). Their crystals feature balanced NLO performances with a large NLO coefficient, wide transparent region, high laser damage threshold, and high polarization ratio. This work demonstrates the promise of naturally abundant amino acids for the construction of hybrid chiral metal halide perovskites for next generation optoelectronic materials.