DC bias electric field effects on ac electrical conductivity of MAPbI(3) suggesting intrinsic changes on structure and charge carrier dynamics

Autor(es)

Minussi, F. B. ^[1] ; Reis, S. P. ^{[1, 2]} ; Araujo, E. B. ^[1]

Afiliação do(s) autor(es)

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

^[2] Fed Inst Educ Sci & Technol Sao Paulo, BR-15503110 Votuporanga - Brazil

• Tipo de documento: Artigo Científico
• Fonte: JOURNAL OF PHYSICS-CONDENSED MATTER; v. 33, n. 47 NOV 24 2021.
• Citações Web of Science: 0

Resumo

Methylammonium lead iodide (MAPbI(3)) emerges as a promising halide perovskite material for the next generation of solar cells due to its high efficiency and flexibility in material growth. Despite intensive studies of their optical and electronic properties in the past ten years, there are no reports on dc bias electric field effects on conductivity in a wide temperature range. In this work, we report the combined effects of frequency, temperature, and dc bias electric field on the ac conductivity of MAPbI(3). We found that the results of dc bias electric fields are very contrasting in the tetragonal and cubic phases. In the tetragonal phase, sufficiently high dc bias electric fields induce a conductivity peak appearance similar to 290 K well evidenced at frequencies higher than 100 kHz. Excluding possible degradation and extrinsic factors, we propose that this peak suggests a ferroelectric-like transition. In the absence of a dc bias electric field, the ac conductivity in the tetragonal phase increases with temperature while decreases with temperature in the cubic phase. Also, ac activation energies for tetragonal and cubic phases were found to be inversely and directly proportional to the dc bias electric field, respectively. This behavior was attributed to the ionic conduction, possibly of MA(+) and I- ions, for the tetragonal phase. As for the cubic phase, the ac conduction dynamics appear to be metallic-like, which seems to change to a polaronic-controlled charge transport to increased dc bias electric fields. (AU)

• Processo FAPESP: 17/13769-1 - Materiais multiferróicos e ferroelétricos para conversores de energia: síntese, propriedades, fenomenologia e aplicações
• Beneficiário: José Antonio Eiras
• Modalidade de apoio: Auxílio à Pesquisa - Temático