Suppressing Strong Exciton–Phonon Coupling in Blue Perovskite Nanoplatelet Solids by Binary Systems

Abstract

Quasi-two-dimensional(2D) perovskites are promising candidates for light generation owing to their high radiative rates.H owever,s trong exciton-phonon interactions caused by mechanical softening of the surface act as ab ottleneck in improving their suitability for awide range of lighting and displayapplications.Moreover,itisnot easily available to tune the phonon interactions in bulk films.H ere,w ea dopt bottom-up fabricated blue emissive perovskite nanoplatelets (NPLs) as model systems to elucidate and as well as tune the phonon interactions via engineering of binary NPL solids.By optimizing component domains,the phonon coupling strength can be reduced by afactor of 2driven by the delocalization of 2D excitons in out-of-plane orientations.I ts hows the picosecond energy transfer originated from the Fçrster resonance energy transfer (FRET) efficiently competes with the excitonphonon interactions in the binary system.

Strong Triplet-Exciton–LO-Phonon Coupling in Two-Dimensional Layered Organic–Inorganic Hybrid Perovskite Single Crystal Microflakes

“…In organic metal halide perovskites, the scattering by ionized impurities does not play a major role, which is neglected here. 39,40 Unlike the LO phonon energy, the coupling strength of the triplet exciton-LO phonon (145.08 meV) is much larger than that of singlet exciton-LO phonon (81.82 meV). This difference can be contributed to the different locations of singlet and triplet excitons in the (PEA)2PbBr4 perovskite with a QW structure.…”

“…The temperaturedependent PL broadening is correlated to the lattice scattering. 39 The total PL spectral broadening can be described by the following formula: 40 13 / 22…”

Activation of Self‐Trapped Emission in Stable Bismuth‐Halide Perovskite by Suppressing Strong Exciton–Phonon Coupling

“…[ 11 ] However, extremely strong exciton–phonon coupling, on the one hand, will cause the excited‐state energy to be dissipated by phonons, which further drives the excited carriers/excitons to recombine nonradiatively by emitting several phonons. [ 11c,12 ] On the other hand, it facilitates excited carriers/excitons being trapped by nonradiative recombination centers (e.g., intrinsic lattice defects or extrinsic impurity defects), thus leading to PL quenching. [ 7d,13 ] Therefore, a high‐efficiency radiative recombination process requires a moderate exciton–phonon coupling effect with a suitable strength.…”

Transformation Pathway from CdSe Magic‐Size Clusters with Absorption Doublets at 373/393 nm to Clusters at 434/460 nm

“…It is worth noting that an understanding of these PL nanospecies and their formation will aid their potential applications such as in optoelectronic displays and solid-state lighting. [52][53][54][55] We anticipate that the PC-enabled pathway (Scheme 1) has general applicability for transformations such as from PL CdSe dMSC-460 to dMSC-513, [36] as well as from PL CdTedMSC-427 to dMSC-495, to dMSC-550, and to dMSC-600. [31] Thepresent findings bring sophisticated insight into the pathway of the MSC evolution and transformation, the latter of which experiences reactions of monomer substitution [1] or addition that transform two MSC counterpart PCs.…”

“…More sophisticated theoretical models are needed to understand the thermodynamics and kinetics of the clusters better, as well as their PC‐enabled formation. It is worth noting that an understanding of these PL nanospecies and their formation will aid their potential applications such as in optoelectronic displays and solid‐state lighting [52–55] . We anticipate that the PC‐enabled pathway (Scheme 1) has general applicability for transformations such as from PL CdSe dMSC‐460 to dMSC‐513, [36] as well as from PL CdTe dMSC‐427 to dMSC‐495, to dMSC‐550, and to dMSC‐600 [31] .…”