Ultrafast Carrier Dynamics in Methylammonium Lead Iodide (MAPbI3) Perovskite Thin Films With Coexisting Orthorhombic and Tetragonal Phases
Li, Yong LU ; Yao, Zehan LU ; Jiao, Chenxu ; Wang, Zhengjun LU ; Schlawin, Frank and Baranov, Dmitry LU
(2026)
In Small Structures
7(6).
- Abstract
Methylammonium lead iodide (MAPbI3) is a prototypical soft-lattice semiconductor whose orthorhombic and tetragonal polymorphs can coexist and interconvert under optical excitation or changes in temperature. The mixed-phase regime attracts attention because of the carrier transfer between phases, which enables optoelectronic functionalities such as optical gain. Here, we investigate carrier dynamics in mixed-phase MAPbI3 thin films by comparing laser-induced phase coexistence at 77 K using time-resolved photoluminescence with thermally-induced phase coexistence at 148 K using transient absorption (TA) spectroscopy. By using low-repetition-rate TA to mitigate cumulative heating and avoid thermally induced phase... (More)
Methylammonium lead iodide (MAPbI3) is a prototypical soft-lattice semiconductor whose orthorhombic and tetragonal polymorphs can coexist and interconvert under optical excitation or changes in temperature. The mixed-phase regime attracts attention because of the carrier transfer between phases, which enables optoelectronic functionalities such as optical gain. Here, we investigate carrier dynamics in mixed-phase MAPbI3 thin films by comparing laser-induced phase coexistence at 77 K using time-resolved photoluminescence with thermally-induced phase coexistence at 148 K using transient absorption (TA) spectroscopy. By using low-repetition-rate TA to mitigate cumulative heating and avoid thermally induced phase conversion, we resolve the distinct spectral fingerprints of the orthorhombic and tetragonal phases and identify two carrier-transfer timescales of 36 and 539 ps, attributed to interfacial and bulk-mediated transfer, respectively. Despite carrier funneling in the mixed phase and high carrier densities, these conditions do not inherently lead to observable optical gain in the studied films.
(Less)
- author
- Li, Yong
LU
; Yao, Zehan
LU
; Jiao, Chenxu
; Wang, Zhengjun
LU
; Schlawin, Frank
and Baranov, Dmitry
LU
- organization
- publishing date
- 2026-06
- type
- Contribution to journal
- publication status
- published
- subject
- keywords
- carrier transfer, halide perovskites, low-temperature photophysics, methylammonium lead iodide (MAPbI), orthorhombic-tetragonal transition, phase coexistence, time-resolved photoluminescence, transient absorption spectroscopy
- in
- Small Structures
- volume
- 7
- issue
- 6
- article number
- e70515
- publisher
- Wiley
- external identifiers
-
- scopus:105042225417
- ISSN
- 2688-4062
- DOI
- 10.1002/sstr.70515
- project
- Nanocrystal Solids for Quantum Technology
- Tennbaserade nanostrukturer för optisk kvantteknologi
- language
- English
- LU publication?
- yes
- additional info
- Publisher Copyright: © 2026 The Author(s). Small Structures published by Wiley-VCH GmbH.
- id
- 494342d0-472d-41c2-a12f-791ab9a3a284
- date added to LUP
- 2026-06-26 17:12:52
- date last changed
- 2026-06-29 08:25:48
@article{494342d0-472d-41c2-a12f-791ab9a3a284,
abstract = {{<p>Methylammonium lead iodide (MAPbI<sub>3</sub>) is a prototypical soft-lattice semiconductor whose orthorhombic and tetragonal polymorphs can coexist and interconvert under optical excitation or changes in temperature. The mixed-phase regime attracts attention because of the carrier transfer between phases, which enables optoelectronic functionalities such as optical gain. Here, we investigate carrier dynamics in mixed-phase MAPbI<sub>3</sub> thin films by comparing laser-induced phase coexistence at 77 K using time-resolved photoluminescence with thermally-induced phase coexistence at 148 K using transient absorption (TA) spectroscopy. By using low-repetition-rate TA to mitigate cumulative heating and avoid thermally induced phase conversion, we resolve the distinct spectral fingerprints of the orthorhombic and tetragonal phases and identify two carrier-transfer timescales of 36 and 539 ps, attributed to interfacial and bulk-mediated transfer, respectively. Despite carrier funneling in the mixed phase and high carrier densities, these conditions do not inherently lead to observable optical gain in the studied films.</p>}},
author = {{Li, Yong and Yao, Zehan and Jiao, Chenxu and Wang, Zhengjun and Schlawin, Frank and Baranov, Dmitry}},
issn = {{2688-4062}},
keywords = {{carrier transfer; halide perovskites; low-temperature photophysics; methylammonium lead iodide (MAPbI); orthorhombic-tetragonal transition; phase coexistence; time-resolved photoluminescence; transient absorption spectroscopy}},
language = {{eng}},
number = {{6}},
publisher = {{Wiley}},
series = {{Small Structures}},
title = {{Ultrafast Carrier Dynamics in Methylammonium Lead Iodide (MAPbI<sub>3</sub>) Perovskite Thin Films With Coexisting Orthorhombic and Tetragonal Phases}},
url = {{http://dx.doi.org/10.1002/sstr.70515}},
doi = {{10.1002/sstr.70515}},
volume = {{7}},
year = {{2026}},
}