Phase transition dynamics in one-dimensional halide perovskite crystals

Journal Article · Thu Feb 25 00:00:00 UTC 2021 · MRS Bulletin

DOI:https://doi.org/10.1557/s43577-021-00047-x· OSTI ID:1832546

Lai, Minliang ^[1]; Lei, Teng ^[2]; Zhang, Ye ^[1]; Jin, Jianbo ^[3]; Steele, Julian A. ^[4]; Yang, Peidong ^[5]

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1. Univ. of California, Berkeley, CA (United States)
2. KU Leuven (Belgium)
3. Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
4. Univ. of California, Berkeley, CA (United States); KU Leuven (Belgium)
5. Univ. of California, Berkeley, CA (United States); Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Kavli Energy NanoScience Inst., Berkeley, CA (United States)

Triiodide perovskites CsPbI₃, CsSnI₃, and FAPbI₃ (where FA is formamidinium) are highly promising materials for a range of optoelectronic applications in energy conversion. However, they are thermodynamically unstable at room temperature, preferring to form low-temperature (low-T) non-perovskite phases with one-dimensional anisotropic crystal structures. While such thermodynamic behavior represents a major obstacle toward realizing high-performance devices based on their high-temperature (high-T) perovskite phases, the underlying phase transition dynamics are still not well understood. Here we use in situ optical micro-spectroscopy to quantitatively study the transition from the low-T to high-T phases in individual CsSnI₃ and FAPbI₃ nanowires. We reveal a large blueshift in the photoluminescence (PL) peak (~38 meV) at the low-T/high-T two-phase interface of partially transitioned FAPbI₃ wire, which may result from the lattice distortion at the phase boundary. Compared to the experimentally derived activation energy of CsSnI₃ (~1.93 eV), the activation energy of FAPbI₃ is relatively small (~0.84 eV), indicating a lower kinetic energy barrier when transitioning from a face-sharing octahedral configuration to a corner-sharing one. Further, the phase propagation rate in CsSnI₃ is observed to be relatively high, which may be attributed to a high concentration of Sn vacancies. Furthermore, our results could not only facilitate a deeper understanding of phase transition dynamics in halide perovskites with anisotropic crystal structures, but also enable controllable manipulation of optoelectronic properties via local phase engineering.

• Research Organization: Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States)
• Sponsoring Organization: USDOE Office of Science (SC), Basic Energy Sciences (BES). Materials Sciences & Engineering Division
• Grant/Contract Number: AC02-05CH11231
• OSTI ID: 1832546
• Journal Information: MRS Bulletin, Journal Name: MRS Bulletin Journal Issue: 4 Vol. 46; ISSN 0883-7694
• Publisher: Materials Research Society
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
CsSnI3
FAPbI3
Halide perovskites
in-situ
phase boundary
phase transition