Negative Thermal Quenching of Efficient White‐Light Emission in a 1D Ladder‐Like Organic/Inorganic Hybrid Material. Issue 20 (12th August 2019)

• Record Type: Journal Article
• Authors: Barkaoui, Hamdi; Abid, Haitham; Zelewski, Szymon; Urban, Joanna; Baranowski, Michal; Mlayah, Adnen; Triki, Smail; Plochocka, Paulina; Abid, Younes
• Is Part Of: Advanced optical materials. Volume 7:Issue 20(2019)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2019-08-12
• Subjects: hybrid organic inorganic -- negative thermal quenching -- photoluminescence -- polaronic states -- self‐trapped excitons -- white‐light emission; Optical materials -- Periodicals; Photonics -- Periodicals; 620.11295
• DOI: 10.1002/adom.201900763
• Languages: English
• ISSNs: 2195-1071

Abstract

Abstract: The synthesis and the optical properties of a new organic–inorganic hybrid material (C6 H22 N4 )[Pb2 Br8 ] (abbreviated as TETAPb2 Br8 ) is reported here. Its ladder‐like crystal structure is built up from infinite 1D chains of corner‐sharing [Pb2 Br8 ] 4− bi‐octahedra surrounded by tetra‐protonated triethylenetetramine (abbreviated as TETA 4+ ) organic cations. Under UV excitation, this hybrid organic–inorganic compound emits white light due to radiative recombinations of self‐trapped excitons associated with a structural distortion of the PbBr6 octahedra. Thin films of TETAPb2 Br8 show a photoluminescence (PL) quantum yield of ≈11% and exhibit a Commission Internationale de l'Eclairage coordinates of (0.32, 0.37). In the low‐temperature range, the PL intensity increases with increasing temperature. This negative thermal quenching of white‐light emission is interpreted in terms of transitions between excitonic states involving an exciton–phonon interaction. The interpretations are supported by the temperature dependence of the resonant Raman scattering and by density functional theory calculations. Abstract : TETAPb2 Br8, a 1D ladder‐like organic–inorganic hybrid compound, emits white light due to radiative recombinations of self‐trapped excitons (STEs). In the low‐temperature range, the photoluminescence intensity as well as the STE lifetime increase with increasing temperature. This negative thermal quenching of emission is due to transitions between polaronic states involving exciton–phonon interaction.