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- Title
Hot carrier cooling mechanisms in halide perovskites.
- Authors
Jianhui Fu; Qiang Xu; Bo Wu; Meng Lee Leek; Tze Chien Sum; Cheng Hon Alfred Huan; Guifang Han
- Abstract
Halide perovskites exhibit unique slow hot-carrier cooling properties capable of unlocking disruptive perovskite photon–electron conversion technologies (e.g., high-efficiency hotcarrier photovoltaics, photo-catalysis, and photodetectors). Presently, the origins and mechanisms of this retardation remain highly contentious (e.g., large polarons, hot-phonon bottleneck, acoustical–optical phonon upconversion etc.). Here, we investigate the fluencedependent hot-carrier dynamics in methylammonium lead triiodide using transient absorption spectroscopy, and correlate with theoretical modeling and first-principles calculations. At moderate carrier concentrations (around 1018 cm−3), carrier cooling is mediated by polar Fröhlich electron–phonon interactions through zone-center delayed longitudinal optical phonon emissions (i.e., with phonon lifetime τLO around 0.6 ± 0.1 ps) induced by the hotphonon bottleneck. The hot-phonon effect arises from the suppression of the Klemens relaxation pathway essential for longitudinal optical phonon decay. At high carrier concentrations (around 1019 cm−3), Auger heating further reduces the cooling rates. Our study unravels the intricate interplay between the hot-phonon bottleneck and Auger heating effects on carrier cooling, which will resolve the existing controversy.
- Subjects
HALIDES; PEROVSKITE; HOT carriers; COOLING; PHOTON-electron interactions
- Publication
Nature Communications, 2017, Vol 8, Issue 1, p1
- ISSN
2041-1723
- Publication type
Article
- DOI
10.1038/s41467-017-01360-3