Perovskites: Multiphoton Absorption and Applications

Abstract Recently, there have been intensive and extensive research works on perovskites because of their excellent electrical and optical properties. This review is focused on their multiphoton absorption (MPA) and applications. All the MPA coefficients or cross‐sections reported in the literature are summarized. Many experimental data show that the MPA strengths of nanoscale perovskites are several orders of magnitude greater than their bulk counterparts. The second‐ and third‐order quantum perturbation theories predict that, while the two‐band transitions play a significant role in 3D crystals of perovskites, the exciton‐light interactions dominate in the case of 2D perovskites. Other influencing factors on the MPA magnitudes are also discussed. Their potential applications are also highlighted in laser‐frequency upconversion and sub‐bandgap photodetection.