激子
光致发光
化学
放松(心理学)
声子
皮秒
极化子
吸收(声学)
电子
凝聚态物理
分子物理学
比克西顿
结合能
电介质
化学物理
原子物理学
材料科学
光电子学
物理
光学
激光器
社会心理学
量子力学
心理学
作者
Daniel B. Straus,Sebastian Hurtado Parra,Natasha Iotov,Julian Gebhardt,Andrew M. Rappe,Joseph E. Subotnik,James M. Kikkawa,Cherie R. Kagan
摘要
Quantum and dielectric confinement effects in Ruddlesden-Popper 2D hybrid perovskites create excitons with a binding energy exceeding 150 meV. We exploit the large exciton binding energy to study exciton and carrier dynamics as well as electron-phonon coupling (EPC) in hybrid perovskites using absorption and photoluminescence (PL) spectroscopies. At temperatures <75 K, we resolve splitting of the excitonic absorption and PL into multiple regularly spaced resonances every 40-46 meV, consistent with EPC to phonons located on the organic cation. We also resolve resonances with a 14 meV spacing, in accord with coupling to phonons with mixed organic and inorganic character. These assignments are supported by density-functional theory calculations. Hot exciton PL and time-resolved PL measurements show that vibrational relaxation occurs on a picosecond time scale competitive with that for PL. At temperatures >75 K, excitonic absorption and PL exhibit homogeneous broadening. While absorption remains homogeneous, PL becomes inhomogeneous at temperatures <75K, which we speculate is caused by the formation and subsequent dynamics of a polaronic exciton.
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