Bright circularly polarized photoluminescence in chiral layered hybrid lead-halide perovskites

Abstract

Hybrid perovskite semiconductor materials are predicted to lock chirality into place and encode asymmetry into their electronic states, while softness of their crystal lattice accommodates lattice strain to maintain high crystal quality with low defect densities, necessary for high luminescence yields. We report photoluminescence quantum efficiencies as high as 39% and degrees of circularly polarized photoluminescence of up to 52%, at room temperature, in the chiral layered hybrid lead-halide perovskites (R/S/Rac)-3BrMBA 2 PbI 4 [3BrMBA = 1-(3-bromphenyl)-ethylamine]. Using transient chiroptical spectroscopy, we explain the excellent photoluminescence yields from suppression of nonradiative loss channels and high rates of radiative recombination. We further find that photoexcitations show polarization lifetimes that exceed the time scales of radiative decays, which rationalize the high degrees of polarized luminescence. Our findings pave the way toward high-performance solution-processed photonic systems for chiroptical applications and chiral-spintronic logic at room temperature.

Chiral-Induced Spin Selectivity Modulated Time-Correlated Single-Photon Counting for DNA Hybridization Detection

“…The nonradiative average decay lifetime of the QD-dsDNA system was calculated to be ∼12.97 ± 0.7 and ∼15.18 ± 0.7 ns for UP and DOWN directions of the magnetic field, respectively. The largest observed decay lifetime difference to date is ∼2.21 ns, achieved in the QD-dsDNA system with different magnetic field orientations. ,,, We calculated the yield of spin polarization using the spin-based nonradiative average decay time of optically excited states of the QD-DNA system. In particular, the yield of spin polarization | P s | was determined by the following equation: | P s | = ⟨ τ ↑ ⟩ + ⟨ τ ↓ ⟩ ⟨ τ ↑ ⟩ − ⟨ τ ↓ ⟩ × 100 where ⟨τ ↑ ⟩ is the nonradiative average decay lifetime when the magnetic field is in an upward direction and ⟨τ ↓ ⟩ is the nonradiative average decay lifetime when the magnetic field is in the downward direction.…”

“…It is noteworthy that the PL intensity remains consistent regardless of the magnetic field direction for the QD-ssDNA system. Quantitatively, the yield of spin polarization of all QD-DNA systems can be expressed as | P s | = I false↑ − I false↓ I false↑ + I false↓ × 100 where I ↑ is the PL intensity when the magnetic field is in an upward direction and I ↓ is the PL intensity when the magnetic field is in a downward direction.…”

Rashba Effect and Spin-Dependent Excitonic Properties in Chiral Two-Dimensional/Three-Dimensional Composite Perovskite Films

“…Given the aforementioned findings, it is plausible to infer that the intrinsic chirality characteristics of chiral 2D/3D CP films will influence the amount of the carrier population. 49 PL signals excited by CPL can be used to characterize the spin-dependent excitonic properties of chiral materials. To overcome the band gap limitation in the application of NIR CPL detection, 22 investigating the spin-dependent excitonic properties of chiral 2D/3D CPs by two-photon excitation is meaningful.…”

“…The outcome for 450 nm excitation was similar (Figures S10 and S11). Given the aforementioned findings, it is plausible to infer that the intrinsic chirality characteristics of chiral 2D/3D CP films will influence the amount of the carrier population …”

Negative Nonlinear CD–ee Dependence in Polycrystalline BINOL Thin Films

“…Ranging from the characterization of enantiomeric compositions to sensorics and optoelectronics, , the demand for understanding and the application of chirality continues to increase . Examples of the importance of chirality in energy conservation and efficient conversion include low energy consumption and large memory density devices and electronics using chiral perovskites − and chirality transfer to transition metal complexes for the application of asymmetric catalysis. − The most common manifestation of optical activity in a system is its circular dichroism (CD), − the preferential absorption of one circular polarization (CP) of light over the other.…”