TY - JOUR
T1 - Screening in crystalline liquids protects energetic carriers in hybrid perovskites
AU - Zhu, Haiming
AU - Miyata, Kiyoshi
AU - Fu, Yongping
AU - Wang, Jue
AU - Joshi, Prakriti P.
AU - Niesner, Daniel
AU - Williams, Kristopher W.
AU - Jin, Song
AU - Zhu, X. Y.
N1 - Funding Information:
The growth of macroscopic single-crystal samples and TR-OKE measurements were supported by the U.S. Department of Energy, Office of Science-Basic Energy Sciences, grant ER46980. The PL experiments were supported by the National Science Foundation, grant DMR 1420634 (Materials ResearchScience and Engineering Center). S.J. acknowledges support by the Department of Energy, Office of Basic Energy Sciences, Division of Materials Sciences and Engineering, under Award DE-FG02 09ER46664, for the growth of microplate samples.We thank D. Paley for help with x- ray diffraction experiment carried out in Columbia University's Shared Materials Characterization Laboratory.
PY - 2016/9/23
Y1 - 2016/9/23
N2 - Hybrid lead halide perovskites exhibit carrier properties that resemble those of pristine nonpolar semiconductors despite static and dynamic disorder, but how carriers are protected from efficient scattering with charged defects and optical phonons is unknown. Here, we reveal the carrier protection mechanism by comparing three single-crystal lead bromide perovskites: CH3NH3PbBr3, CH(NH2)2PbBr3, and CsPbBr3.We observed hot fluorescence emission from energetic carriers with ~102 picosecond lifetimes in CH3NH3PbBr3 or CH(NH2)2PbBr3, but not in CsPbBr3.The hot fluorescence is correlated with liquid-like molecular reorientational motions, suggesting that dynamic screening protects energetic carriers via solvation or large polaron formation on time scales competitive with that of ultrafast cooling. Similar protections likely exist for band-edge carriers.The long-lived energetic carriers may enable hot-carrier solar cells with efficiencies exceeding the Shockley-Queisser limit.
AB - Hybrid lead halide perovskites exhibit carrier properties that resemble those of pristine nonpolar semiconductors despite static and dynamic disorder, but how carriers are protected from efficient scattering with charged defects and optical phonons is unknown. Here, we reveal the carrier protection mechanism by comparing three single-crystal lead bromide perovskites: CH3NH3PbBr3, CH(NH2)2PbBr3, and CsPbBr3.We observed hot fluorescence emission from energetic carriers with ~102 picosecond lifetimes in CH3NH3PbBr3 or CH(NH2)2PbBr3, but not in CsPbBr3.The hot fluorescence is correlated with liquid-like molecular reorientational motions, suggesting that dynamic screening protects energetic carriers via solvation or large polaron formation on time scales competitive with that of ultrafast cooling. Similar protections likely exist for band-edge carriers.The long-lived energetic carriers may enable hot-carrier solar cells with efficiencies exceeding the Shockley-Queisser limit.
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U2 - 10.1126/science.aaf9570
DO - 10.1126/science.aaf9570
M3 - Article
AN - SCOPUS:84989869473
VL - 353
SP - 1409
EP - 1413
JO - Science
JF - Science
SN - 0036-8075
IS - 6306
ER -