PhysChem Seminar: Wed Sept 14, 9:30; Layan Hamodi (Lifshitz)

Sep 14th

חדר סמינרים


Layan Hamodi, research was conducted under the supervision of Prof. Efrat Lifshitz

Lanthanide doped in 2D perovskite: from synthesis to the structural and optical characterization

Perovskite nanocrystals (NCs) surged into prominence as a new class of semiconductors at the forefront of research interest. Early efforts showed the vast potential of perovskites as an absorbing layer in photovoltaics and have triggered numerous fundamental studies of their features. Two- and three-dimensional perovskite compounds (e.g., ABX3, A=Cs+, MA+; B=Pb, Bi; X=halides) have been synthesized recently. All mentioned materials are of considerable interest for implementation in various optoelectronic, spin-electronics, memory, and quantum computation.

The two-dimensional halide perovskites are particularly interesting as 2D semiconductors in their higher stability and strong luminescence after an era marked by 3D halide perovskites. Bearing a generic formula, A’2An-1BnX3n+1 (A’-site: van der Waals (vdW) ligands between the perovskite layers, A-site: counter cation, B-site: heavy metal, X-site: halogen, and n: number of perovskite layers).

Most studies have focused on exploring the physical properties of pristine 2D compounds. At the same time, an interest in the formation and physics of electrically or magnetically doped derivatives and alloying compositions was investigated to a lesser extent.

Firstly, we synthesized 2D perovskite (n=1,2,3), where the parameter n denotes the number of individual B-X octahedron layers. Then, we doped 2D perovskite (n=1) ((PEA)2PbI4) with lanthanides (Yb3+, Er3+, Tb3+), particularly focusing on ytterbium-doped (PEA)2PbI4. We demonstrated a facile, low-cost synthesis of ytterbium-doped (PEA)2PbI4 using a simple methodcontrol the size of the single crystals by changing the concentration of the dissolved crystals in the recrystallization method.

Rare earth dopants (Yb3+, Er3+, Tb3+) with d-f and f-f transitions inside the perovskite bandgap are under consideration. Doping is achieved through a simple solution process, followed by structural, morphological, and chemical analysis. The main scientific questions concern photophysical and structural changes in (PEA)2PbI4 layered perovskites doped with lanthanide.

We observed structural changes and new morphology in the doped sample and the appearance of ytterbium isotopes.

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