Autor(es)

Minussi, F. B. ^[1] ; Silva, L. A. ^[2] ; Araujo, E. B. ^[1]

Afiliação do(s) autor(es)

^[1] Sao Paulo State Univ, Dept Phys & Chem, BR-15385000 Ilha Solteira - Brazil

^[2] Univ Rio Verde, Dept Engn, BR-75901970 Rio Verde - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Physical Chemistry Chemical Physics; v. 24, n. 8, p. 4715-4728, FEB 23 2022.
• Citações Web of Science: 0

Resumo

Halide perovskites are a well-known class of materials with many interesting applications. Great attention has been devoted to investigating halide perovskites containing triple methylammonium (MA(+)), formamidinium (FA(+)), and guanidinium (GA(+)) cations. Despite presenting very good applied perspectives so far, the lack of fundamental information for this system, such as its structural, thermal, and optoelectronic characteristics, prompts a step back before any technological leap forward. In the present work, we investigate the physical properties of mechanochemically solvent-free synthesized GA(x)FA(x)MA(1-2x)PbI(3) halide perovskite powders with compositions of 0.00 <= x <= 0.15. We demonstrate that the synthesis of the powders can be performed by a simple manual mechanical grinding of the precursors for about 40 minutes, leading to solid solutions with an only minor content of unreacted precursors. X-ray diffraction, differential scanning calorimetry, and infrared spectroscopy techniques were used to investigate the structure, tetragonal-to-cubic phase transition, and vibrational characteristics of the organic cations with increasing GA(+) and FA(+) contents, respectively. The band gap and Urbach energies, obtained from ultraviolet-visible spectroscopy analyses, ranged from 1.58 to 1.65 eV and 23 to 36 meV, respectively, depending on the composition. These parameters demonstrate a non-random variation with x composition, which offers the possibility of a rational composition design for a given set of desired properties, demonstrating potential for optoelectronic applications. Finally, the system appears to have adequately tolerated heating for 12 hours at 120 degrees C in an ambient atmosphere, indicating high thermal stability and low ionic conductivity, which are desirable characteristics for solar cell applications. (AU)

• Processo FAPESP: 17/13769-1 - MATERIAIS MULTIFERROICOS E FERROELÉTRICOS PARA CONVERSORES DE ENERGIA:Síntese, Propriedades, Fenomenologia e Aplicações.
• Beneficiário: José Antonio Eiras
• Modalidade de apoio: Auxílio à Pesquisa - Temático