Nouvelle publication de l’équipe CIEl : « Yellowish White-Light Emission Involving Resonant Energy Transfer in a New One-Dimensional Hybrid Material: (C9H10N2)PbCl4«
Hamdi Barkaoui, Haitham Abid, Aymen Yangui, Smail Triki, Kamel Boukheddaden, and Younes Abid
DOI: 10.1021/acs.jpcc.8b06850
The present work deals with a new one-dimensional (1D) organic-inorganic hybrid material namely (C9H10N2)PbCl4 (abbreviated as AQPbCl4). Its crystal structure is built up from infinite 1D chain of edge-sharing PbCl6 octahedra surrounded by 3-aminoquinoline (abbreviated as AQ) organic molecules. Contrary to the most organic-inorganic hybrid materials, where the organic moieties act as barriers and the inorganic parts play the role of quantum wells, both inorganic and organic parts in AQPbCl4 are optically active, giving rise to optical properties involving the competition and the interaction of two organic and inorganic emitting entities. Under UV excitation, this hybrid compound shows a strong yellowish white-light emission that can be seen even with the naked eye and at room temperature. Photoluminescence spectrum is composed from a strong and broad yellow band at 538 nm associated with π-π* transition localized within AQ organic molecule and a less intense band in the UV region at 340nm associated with inorganic Wannier exciton confined in the PbCl4 inorganic wires. These attributions were made possible thanks to comparisons with homologous materials and it was supported by theoretical band structure calculations. In addition, both theoretical and experimental results suggest that the emission involves resonant energy transfer mechanism in which the inorganic PbCl4 wires act as a donor and the organic molecules act as an acceptor. Moreover, the temperature dependence study of the photoluminescence led to an estimation of the binding energies of interacting excitons and showed that the energy transfer mechanism is characterized by a remarkable enhancement of the emission band intensity.