Abstract
Understanding carrier relaxation in lead halide perovskites at the nanoscale is critical for advancing their device physics. Here, we directly image carrier cooling in polycrystalline CH3NH3PbI3 films with nanometer spatial resolution. We observe that upon photon absorption, highly energetic carriers rapidly thermalize with the lattice at different rates across the film. The initial carrier temperatures vary by many multiples of the lattice temperature across hundreds of nanometers, a factor that cannot be accounted for by excess photon energy above the bandgap alone or in variations of the initial carrier density. Electron microscopy suggests that morphology plays a critical role in determining the initial carrier temperature and that carriers in small crystal domains decay slower than those in large crystal domains. Our results demonstrate that local disorder dominates the observed carrier behavior, highlighting the importance of making local rather than averaged measurements in these materials.
| Original language | English |
|---|---|
| Pages (from-to) | 1044-1048 |
| Number of pages | 5 |
| Journal | Nano Letters |
| Volume | 18 |
| Issue number | 2 |
| DOIs | |
| Publication status | Published - Feb 14 2018 |
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Keywords
- carriers
- cooling
- microscopy
- Perovskite
- ultrafast
ASJC Scopus subject areas
- Bioengineering
- Chemistry(all)
- Materials Science(all)
- Condensed Matter Physics
- Mechanical Engineering
Cite this
Ultrafast Imaging of Carrier Cooling in Metal Halide Perovskite Thin Films. / Nah, Sanghee; Spokoyny, Boris M.; Soe, Chan M.M.; Stoumpos, Constantinos C.; Kanatzidis, Mercouri G; Harel, Elad.
In: Nano Letters, Vol. 18, No. 2, 14.02.2018, p. 1044-1048.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Ultrafast Imaging of Carrier Cooling in Metal Halide Perovskite Thin Films
AU - Nah, Sanghee
AU - Spokoyny, Boris M.
AU - Soe, Chan M.M.
AU - Stoumpos, Constantinos C.
AU - Kanatzidis, Mercouri G
AU - Harel, Elad
PY - 2018/2/14
Y1 - 2018/2/14
N2 - Understanding carrier relaxation in lead halide perovskites at the nanoscale is critical for advancing their device physics. Here, we directly image carrier cooling in polycrystalline CH3NH3PbI3 films with nanometer spatial resolution. We observe that upon photon absorption, highly energetic carriers rapidly thermalize with the lattice at different rates across the film. The initial carrier temperatures vary by many multiples of the lattice temperature across hundreds of nanometers, a factor that cannot be accounted for by excess photon energy above the bandgap alone or in variations of the initial carrier density. Electron microscopy suggests that morphology plays a critical role in determining the initial carrier temperature and that carriers in small crystal domains decay slower than those in large crystal domains. Our results demonstrate that local disorder dominates the observed carrier behavior, highlighting the importance of making local rather than averaged measurements in these materials.
AB - Understanding carrier relaxation in lead halide perovskites at the nanoscale is critical for advancing their device physics. Here, we directly image carrier cooling in polycrystalline CH3NH3PbI3 films with nanometer spatial resolution. We observe that upon photon absorption, highly energetic carriers rapidly thermalize with the lattice at different rates across the film. The initial carrier temperatures vary by many multiples of the lattice temperature across hundreds of nanometers, a factor that cannot be accounted for by excess photon energy above the bandgap alone or in variations of the initial carrier density. Electron microscopy suggests that morphology plays a critical role in determining the initial carrier temperature and that carriers in small crystal domains decay slower than those in large crystal domains. Our results demonstrate that local disorder dominates the observed carrier behavior, highlighting the importance of making local rather than averaged measurements in these materials.
KW - carriers
KW - cooling
KW - microscopy
KW - Perovskite
KW - ultrafast
UR - http://www.scopus.com/inward/record.url?scp=85042079544&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85042079544&partnerID=8YFLogxK
U2 - 10.1021/acs.nanolett.7b04520
DO - 10.1021/acs.nanolett.7b04520
M3 - Article
VL - 18
SP - 1044
EP - 1048
JO - Nano Letters
JF - Nano Letters
SN - 1530-6984
IS - 2
ER -