The Journal of Physical Chemistry Letters最新文献

Nickel oxide (NiO_x) is one of the most widely employed hole transport layers (HTLs) in inverted perovskite solar cells (PSCs) due to its low-temperature processability, compatibility with scalable fabrication, and favorable energy-level alignment. Since 2015, extensive efforts have been devoted to enhancing the optoelectronic properties of NiO_x; however, most studies have predominantly focused on planar NiO_x (pNiO_x) films. In this study, we fabricate a mesoporous nickel oxide (mNiO_x) HTL via high-temperature calcination, using nickel nitrate hexahydrate (Ni(NO₃)₂·6H₂O) as the nickel precursor, Pluronic P123 and a small amount of polyvinylpyrrolidone (PVP) as structure-directing templates. The resulting mesoporous framework modulates the perovskite crystallization kinetics, enhances the buried interface, improves the crystallization quality, reduces the defect density, and shifts the interfacial stress state from tensile to compressive. Consequently, both the open-circuit voltage (V_OC) and fill factor (FF) of the devices are significantly enhanced. The PSCs based on the mNiO_x HTL achieve a power conversion efficiency (PCE) of 23.19%, along with markedly improved operation and storage stability.

In this work, we systematically investigate the lattice thermal conductivity (κ_L) of LaMoN₃ in the C2/c and R3c phases using first-principles calculations combined with the Boltzmann transport equation. In the C2/c phase, κ_L exhibits strong anisotropy, with values of 0.75 W/mK, 1.89 W/mK, and 0.82 W/mK along the a, b, and c axes, respectively, at 300 K. In contrast, the R3c phase shows nearly isotropic thermal conductivity, with values of 6.28 W/mK, 7.05 W/mK, and 7.31 W/mK along the a, b, and c directions. In both phases, acoustic and low-frequency optical phonons dominate the thermal transport. However, the C2/c phase exhibits increased three-phonon scattering leading to smaller values of κ_L. Additionally, four-phonon scattering plays a dominant role in the C2/c phase, reducing κ_L by approximately 96%, whereas in the R3c phase, it leads to a smaller but still significant reduction of ∼50%. These results highlight the critical role of four-phonon interactions in determining the thermal transport properties of LaMoN₃ and reveal the stark contrast in thermal conductivity between its two structural phases.

Isotope-selective photodissociation is a promising route to laser-based separation, yet its efficiency remains constrained by fixed molecular cross sections. Here, we introduce an active optical-switching strategy that utilizes a nonresonant ultraviolet control pulse to generate and tailor isotopologue-specific Fano resonances. By coupling high-lying vibrational levels of the electronic ground state to a dissociative continuum, this pulse dynamically modulates photodissociation cross sections without direct electronic excitation. Using full quantum wave packet simulations of HF and DF isotopologues, we demonstrate that the photofragment yield ratio can be reversibly switched by orders of magnitude through tuning of the probe frequency across a light-induced resonance. This approach enables selective suppression or enhancement of dissociation for a target isotopologue with high spectral precision. Our work establishes a versatile and efficient mechanism for isotope-selective photochemistry and opens a pathway toward coherent optical control of molecular photodissociation.