Strong two-photon absorption induced by energy funneling in chiral quasi-2D perovskites

Abstract

Quasi-2D Ruddlesden–Popper-type perovskites (RPPs) exhibit excellent nonlinear optical properties due to their multiple quantum well structures with large exciton binding energy. Herein, we introduce chiral organic molecules into RPPs and investigate their optical properties. It is found that the chiral RPPs possess effective circular dichroism in the ultraviolet to visible wavelengths. Two-photon absorption (TPA)-induced efficient energy funneling from small- to large-n domains is observed in the chiral RPP films, which induces strong TPA with a coefficient up to 4.98 cm MW−1. This work will broaden the application of quasi-2D RPPs in chirality-related nonlinear photonic devices.

Spatially Correlated Chirality in Chiral Two-Dimensional Perovskites Revealed by Second-Harmonic-Generation Circular Dichroism Microscopy

“…Such strong TPA is attributed to the strong quantum confinement within the 2D [PbBr 6 ] 4− layers, which makes R-and S-MBPB valuable for applications in nonlinear optoelectronic devices, such as sub-bandgap circularly polarized photodetectors. 38,52,53 The good photostability of NLO materials is crucial for practical applications, so we further investigated the stability of R-MBPB under continuous femtosecond laser irradiation. As plotted in Figure 3f, R-MBPB maintained 85% of the initial SHG intensity after continuous irradiation over 20 min with an incident optical intensity of 7.86 GW cm −2 , while the TPPL intensity remained <10% of the initial value upon irradiation with a much lower optical intensity (1.96 GW cm −2 ).…”

“…Additionally, the TPA coefficient of R -MBPB was determined to be 1.25 cm MW –1 at 800 nm by the open-aperture Z-scan technique (Figure S14; see Supplementary Note 4). Such strong TPA is attributed to the strong quantum confinement within the 2D [PbBr 6 ] 4– layers, which makes R - and S -MBPB valuable for applications in nonlinear optoelectronic devices, such as sub-bandgap circularly polarized photodetectors. ,, …”

Rashba Effect and Spin-Dependent Excitonic Properties in Chiral Two-Dimensional/Three-Dimensional Composite Perovskite Films

“…It has been proven that long-chain chiral ligands can be used for the synthesis of chiral 2D HPs . In addition, the rapid emergence of chiral 2D/three-dimensional (3D) composite perovskites (CPs) offers an opportunity to combine the chirality and effective photoluminescence (PL) to realize practical device applications, − which exhibit a facile preparation approach, tunable optical properties, outstanding nonlinear optical properties, and spintronic conduction. − Compared with general chiral 2D HPs, chiral 2D/3D CPs may possess various advantages. For example, the latter may possess significant interface asymmetry and an effective energy transfer process.…”