| Full text | |
| Author(s): |
Sombrio, G.
[1]
;
Zhang, Z.
[2]
;
Bonadio, A.
[1]
;
de Oliveira, L. S.
[1]
;
de Queiroz, T. B.
[1]
;
Ferreira, F. F.
[1]
;
Janotti, A.
[2]
;
Souza, J. A.
[1]
Total Authors: 8
|
| Affiliation: | [1] Univ Fed ABC, Santo Andre, SP - Brazil
[2] Univ Delaware, Dept Mat Sci & Engn, Newark, DE 19716 - USA
Total Affiliations: 2
|
| Document type: | Journal article |
| Source: | Journal of Physical Chemistry C; v. 124, n. 20, p. 10793-10803, MAY 21 2020. |
| Web of Science Citations: | 0 |
| Abstract | |
Methylammonium lead iodide (MAPbI(3)) is a very promising semiconducting material for photovoltaic applications. Despite extensive research and tremendous progress, basic charge transport properties are still being debated. Combining first-principles calculations and macroscopic and local measurements, we have investigated the structural, optical, thermal, and electrical transport (ac/dc) properties of MAPbI(3) hot-pressed pellets through the tetragonal-to-cubic phase transition. Thermal analysis and X-ray diffraction experiments confirm the tetragonal-to-cubic phase change around T-S = 56 degrees C, which is often close to the working temperature of photovoltaic devices. The ac/dc electrical resistivities of the tetragonal phase indicate a metallic-like behavior as a function of temperature followed by an abrupt decrease in the cubic phase just above T-S. In contrast to the abrupt changes observed in the electrical properties, the bandgap energy is barely affected across the phase transition. Similarly, local measurements obtained by means of nuclear magnetic resonance confirm a continuous variation in the lattice parameters and site symmetry (Pb-207 and I-127) across the structural phase transition. Density functional theory calculations combined with electrical characterizations indicate that iodine and/or unintentionally incorporated hydrogen interstitials influence decisively the charge transport activation energy in the cubic phase. In light of these findings, the unusual electrical resistivity behavior across the phase transition is discussed taking the grain boundary effects into consideration. (AU) | |
| FAPESP's process: | 19/01785-8 - Synthesis and characterization of CH3NH3PbX3 perovskites films |
| Grantee: | Guilherme Sombrio |
| Support Opportunities: | Scholarships in Brazil - Post-Doctoral |
| FAPESP's process: | 17/02317-2 - Interfaces in materials: electronic, magnetic, structural and transport properties |
| Grantee: | Adalberto Fazzio |
| Support Opportunities: | Research Projects - Thematic Grants |
| FAPESP's process: | 18/15682-3 - Synthesis and Physical Properties Characterization of Micro/Nanostructured Semiconducting Materials |
| Grantee: | José Antonio Souza |
| Support Opportunities: | Regular Research Grants |