Triple Threshold Transitions and Strong Polariton Interaction in 2D Layered Metal–Organic Framework Microplates

Abstract

Room‐temperature interaction between light–matter hybrid particles such as exciton–polaritons under extremely low‐pump plays a crucial role in future coherent quantum light sources. However, the practical and scalable realization of coherent quantum light sources operating under low‐pump remains a challenge because of the insufficient polariton interaction strength. Here, at room temperature, a very large polariton interaction strength is demonstrated, g ≈ 128 ± 21 µeV µm2 realized in a 2D nanolayered metal–organic framework (MOF). As a result, a polariton lasing at an extremely low pump fluence of P1 ≈ 0.01 ± 0.0015 µJ cm−2 (first threshold) is observed. Interestingly, as pump fluence increases to P2 ≈ 0.031 ± 0.003 µJ cm−2 (second threshold), a spontaneous transition to a polariton breakdown region occurs, which has not been reported before. Finally, an ordinary photon lasing occurs at P3 ≈ 0.11 ± 0.077 µJ cm−2 (third threshold), or above. These experiments and the theoretical model reveal new insights into the transition mechanisms characterized by three distinct optical regions. This work introduces MOF as a new type of quantum material, with naturally formed polariton cavities, that is a cost‐effective and scalable solution to build microscale coherent quantum light sources and polaritonic devices.

Dynamically responsive photonic metal–organic frameworks

“… 148 Particularly, the lasing thresholds are in the range from 0.34 to 0.12 μJ cm−2 upon various optical pumping conditions, mainly owing to the exciton–polariton lasing mechanism as well as the large MPA cross sections of the three dye-coordinated MOF microplates. Subsequently, they continued to demonstrate the stack of 2D nanosheets of rhodamine B molecular network for constructing a MOF with a large polariton–polariton scattering strength (g) 149 . In 2022, Liu et al.…”

“…Subsequently, they continued to demonstrate the stack of 2D nanosheets of rhodamine B molecular network for constructing a MOF with a large polariton-polariton scattering strength (g). 149 In 2022, Liu et al employed a mixed ligand strategy to synthesize a series of MPA frameworks in combination of AIE-linker H 4 TCPE and four pillared D-π-A ligands [1,4-bis(4-pyridylethenyl) benzene (L1), 1,4-bis(4-pyridylethenyl)-naphthalene (L2), 9,10bis(4-pyridylethenyl)anthracene (L3, An2Py), and 4,9-bis (4-pyridylethenyl)pyrene (L4)]. 150 Complex 1 and isostructural complexes 2 to 5 exhibited efficient multiphoton excited photoluminescence (MEPL) performance and THG performance.…”