Study of structural, optical and photoconductivity properties in 2D Halide Perovskite

Study of structural, optical and photoconductivity properties in 2D Halide Perovskite

• Autor
• Leonardo José Quintero Da Cuna
• Co-autores
• Prof. Dr. Jose Antonio Souza
• Resumo

• Organic-inorganic halide perovskites and their low 2D dimensional counterpart have attracted a lot of attention in the development of new optoelectronic technologies. The two-dimensional Ruddlesden-Popper (RP) perovskites have crystal structure versatility and improved long-term stability when subjected to light, moisture, and thermal stress. These perovskite crystals are structured as n-layer inorganic octahedral sheets, (OM)2(CH3NH3)n-1PbnI3n+1, sandwiched by two layers of large organic molecules (OM) spacer acting as quantum well barriers. Here, we have synthesized RP samples by using N-butylamine (BA) molecules as a spacer BA2MAn-1PbnI3n+1 for n = 1, 2, 3, 4 and n = ? (3D) and MA=CH3NH3+ (methylammonium). Powder X-ray diffraction indicated that the samples for n = 1, 2, 3 and 4 crystallizes in an orthorhombic crystalline structure while n = ? shows Bragg reflections belonging to a tetragonal structure. Scanning electron microscopy (SEM) images confirm the characteristic 2D lamellar morphology. The 3D structures have irregular rounded particles, with an approximate between 25 ?m to 60 ?m. The quantum confinement effect presented in the octahedral sheets leads to a blue-shifted emission peak. Thus, we have observed an emitted photon energy progressively decreasing from 2.38 eV (n=1) to 1.50 eV (n=?). Electrical conductivity measurements, with light and without light, as a function the number octahedral sheets are being carried out in order to observe the effect of quantum confinement on the photoinduced charge carriers. The study of the structural, morphological, optical, and electrical properties of these 2D samples will be rationalized involving separation and charge transfer processes. Our study may reveal if these 2D systems can represent a possible alternative for use in energy conversion technologies.

   

• Palavras-chave
• Photoconductivity, Perovskite
• Modalidade
• Pôster
• Área Temática
• Materiais Funcionais Avançados