Quantum mechanics

Metallurgy

Materials science

Chromatography

Coupling (piping)

Energy (signal processing)

Absorption (acoustics)

Phonon

Perovskite (structure)

Photoluminescence

Physics

Exciton

Condensed matter physics

Composite material

Analytical Chemistry (journal)

Crystallography

Coupling strength

Chemistry

Optoelectronics

The Journal of Physical Chemistry Letters

The temperature dependence of absorption and photoluminescence (PL) spectroscopies were used to study the optical properties of 2D perovskite films, including n = 1 and 3 of (PEA)2(CH3NH3) n-1[Pb nI3 n+1] (PEA = C6H5(CH2)2NH3). In (PEA)2[Pb1I4] (PEPI), excitons coupling to optical phonons with an average energy of ∼30 meV dominate the photophysics of absorption and PL. (PEA)2(CH3NH3)2[Pb3I10] (shortened as PMPI3), nominally prepared as n = 3, actually was a mixture of multiple layered perovskites with various n. In absorption, a PMPI3 film presents respective n materials' excitonic features, coupling to phonons with an average energy of ∼30 meV; in analyzing PL peaked singly at ∼1.6 eV and its width as a function of temperature, we found that PMPI3 behaves like PEPI at around 80 K but like 3D perovskite near room temperature, with three times larger electron-phonon interaction strength compared to that in PEPI.

Optical Properties of Two-Dimensional Perovskite Films of (C6H5C2H4NH3)2[PbI4] and (C6H5C2H4NH3)2 (CH3NH3)2[Pb3I10]