TY - JOUR
T1 - Anti-Stokes photoluminescence from CsPbBr3 nanostructures embedded in a Cs4PbBr6 crystal
AU - Kajino, Yuto
AU - Otake, Shuji
AU - Yamada, Takumi
AU - Kojima, Kazunobu
AU - Nakamura, Tomoya
AU - Wakamiya, Atsushi
AU - Kanemitsu, Yoshihiko
AU - Yamada, Yasuhiro
N1 - Funding Information:
Acknowledgments. The authors would like to thank Professor S. Chichibu and Professor K. Oto for their cooperation during this work. Part of this work was supported by JST-CREST (Grant No. JPMJCR16N3), JSPS KAKENHI (Grants No. JP19K03683 and No. JP19H05465), the Canon Foundation, and the Chiba Iodine Resource Innovation Center.
Publisher Copyright:
© 2022 American Physical Society.
PY - 2022/4
Y1 - 2022/4
N2 - Lead halide perovskites possess high photoluminescence (PL) efficiency and strong electron-phonon interactions, and therefore optical cooling using up-conversion PL has been expected. We investigate anti-Stokes PL from green-luminescent Cs4PbBr6, whose origin is attributable to CsPbBr3 nanostructures embedded in a Cs4PbBr6 crystal. Because of the high transparency, low refractive index, and high stability of Cs4PbBr6, the green PL displays high external quantum efficiency without photodegradation. Time-resolved PL spectroscopy reveals the excitonic behaviors in the recombination process. The shape of the PL spectrum is almost independent of excitation photon energy, which means that the spectral width is determined by homogeneous broadening. We demonstrate that the phonon-assisted process dominates the Urbach tail of optical absorption and anti-Stokes PL at room temperature. Anti-Stokes PL is observed down to 70 K. We determine the temperature dependence of the Urbach energy and estimate the strength of the electron-phonon coupling. Our spectroscopic data show that CsPbBr3 nanostructures have potentially useful features for optical cooling.
AB - Lead halide perovskites possess high photoluminescence (PL) efficiency and strong electron-phonon interactions, and therefore optical cooling using up-conversion PL has been expected. We investigate anti-Stokes PL from green-luminescent Cs4PbBr6, whose origin is attributable to CsPbBr3 nanostructures embedded in a Cs4PbBr6 crystal. Because of the high transparency, low refractive index, and high stability of Cs4PbBr6, the green PL displays high external quantum efficiency without photodegradation. Time-resolved PL spectroscopy reveals the excitonic behaviors in the recombination process. The shape of the PL spectrum is almost independent of excitation photon energy, which means that the spectral width is determined by homogeneous broadening. We demonstrate that the phonon-assisted process dominates the Urbach tail of optical absorption and anti-Stokes PL at room temperature. Anti-Stokes PL is observed down to 70 K. We determine the temperature dependence of the Urbach energy and estimate the strength of the electron-phonon coupling. Our spectroscopic data show that CsPbBr3 nanostructures have potentially useful features for optical cooling.
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U2 - 10.1103/PhysRevMaterials.6.L043001
DO - 10.1103/PhysRevMaterials.6.L043001
M3 - Article
AN - SCOPUS:85128702115
SN - 2475-9953
VL - 6
JO - Physical Review Materials
JF - Physical Review Materials
IS - 4
M1 - L043001
ER -