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Vibrational fingerprint of localized excitons in a two-dimensional metal-organic crystal.

ABSTRACT: Long-lived excitons formed upon visible light absorption play an essential role in photovoltaics, photocatalysis, and even in high-density information storage. Here, we describe a self-assembled two-dimensional metal-organic crystal, composed of graphene-supported macrocycles, each hosting a single FeN₄ center, where a single carbon monoxide molecule can adsorb. In this heme-like biomimetic model system, excitons are generated by visible laser light upon a spin transition associated with the layer 2D crystallinity, and are simultaneously detected via the carbon monoxide ligand stretching mode at room temperature and near-ambient pressure. The proposed mechanism is supported by the results of infrared and time-resolved pump-probe spectroscopies, and by ab initio theoretical methods, opening a path towards the handling of exciton dynamics on 2D biomimetic crystals.

SUBMITTER: Corva M

PROVIDER: S-EPMC6224418 | biostudies-literature | 2018 Nov

REPOSITORIES: biostudies-literature

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Vibrational fingerprint of localized excitons in a two-dimensional metal-organic crystal.

Corva M M Ferrari A A Rinaldi M M Feng Z Z Roiaz M M Rameshan C C Rupprechter G G Costantini R R Dell'Angela M M Pastore G G Comelli G G Seriani N N Vesselli E E

Nature communications 20181108 1

Long-lived excitons formed upon visible light absorption play an essential role in photovoltaics, photocatalysis, and even in high-density information storage. Here, we describe a self-assembled two-dimensional metal-organic crystal, composed of graphene-supported macrocycles, each hosting a single FeN<sub>4</sub> center, where a single carbon monoxide molecule can adsorb. In this heme-like biomimetic model system, excitons are generated by visible laser light upon a spin transition associated w ...[more]

PMID: 30409974

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