Charge photogeneration and recombination dynamics in non-fullerene solar cells based on a polymer donor with a mono-fluorinated π-bridge.

Non-symmetric fluorine substitution is an important route for designing π-conjugated polymers for high-performance solar cells. However, excited state dynamics in a non-symmetric fluorinated polymer and solar cells are poorly understood. In this work, excited state dynamics in a neat mono-fluorinated polymer (PTzBI-F) film and blend films (PTzBI-F:Y6) were studied using time-resolved spectroscopy.

Charge photogeneration dynamics in non-fullerene polymer solar cells with fluorinated and non-fluorinated acceptors.

In this work, charge photogeneration and recombination processes of PM6:IDIC-4F and PM6:IDIC blend films were investigated by the steady-state and time-resolved spectroscopies, as well as the time-dependent density functional theory calculations. The peaks in absorption and photoluminescence (PL) spectra of IDIC and IDIC-4F solutions were assigned by combining the experiment and the simulation of UV-vis absorption and PL spectra. For neat acceptor films, the exciton diffusion length of neat IDIC and IDIC-4F films was estimated as ∼28.

Ultrahigh UV Responsivity Quasi-Two-Dimensional BiSnO Films Achieved through Surface Reaction.

In this study, quasi-two-dimensional BiSnO (BTO) thin films were fabricated using a liquid metal transfer method. The ultraviolet (UV) photodetector based on BTO thin films was constructed, and the ultrahigh responsivity of 589 A/W was observed at 300 nm UV light illumination. Interestingly, by dropping ethanol during light-off period, the recovery time induced by the persistent photoconductivity (PPC) effect is reduced from 1.

Synergistic Enhancement of Near-Infrared Emission in CsPbCl Host via Co-Doping with Yb and Nd for Perovskite Light Emitting Diodes.

Perovskite nanocrystals (PeNCs) have emerged as a promising class of luminescent materials offering size and composition-tunable luminescence with high efficiency and color purity in the visible range. PeNCs doped with Yb ions, known for their near-infrared (NIR) emission properties, have gained significant attention due to their potential applications. However, these materials still face challenges with weak NIR electroluminescence (EL) emission and low external quantum efficiency (EQE), primarily due to undesired resonance energy transfer (RET) occurring between the host and Yb ions, which adversely affects their emission efficiency and device performance.

How organic switches grafting on TiO modifies the surface potentials: theoretical insights.

Hybrid organic switch-inorganic semiconductor systems have important applications in both photo-responsive intelligent surfaces and microfluidic devices. In this context, herein, we performed first-principles calculations to investigate a series of organic switches of /-azobenzene fluoride and pristine/oxidized trimethoxysilane adsorbed on low-index anatase slabs. The trends in the surface-adsorbate interplay were examined in terms of the electronic structures and potential distributions.

Competition of Carrier Kinetics Contributes to Amplified Spontaneous Emission in Quasi-2D/3D (PBA)MAPbBr Thin Films under Strip Light Mode.

Quasi-2D halide perovskites have potential in lasing due to their amplified spontaneous emission (ASE) properties. The ASE of (PBA)MAPbBr thin films has been confirmed by photoluminescence (PL) testing using stripe light excitation (SLE). The ASE threshold decreases with decreasing environmental temperature () or increasing number of inorganic layers ().

Quantum transports in two-dimensions with long range hopping.

We investigate the effects of disorder and shielding on quantum transports in a two dimensional system with all-to-all long range hopping. In the weak disorder, cooperative shielding manifests itself as perfect conducting channels identical to those of the short range model, as if the long range hopping does not exist. With increasing disorder, the average and fluctuation of conductance are larger than those in the short range model, since the shielding is effectively broken and therefore long range hopping starts to take effect.

Srdoped CsPbBrIperovskite nanocrystals coated with ZrOfor applications as white LEDs.

Perovskite nanocrystals (NCs) feature adjustable bandgap, wide absorption range, and great color purity for robust perovskite optoelectronic applications. Nevertheless, the absence of lasting stability under continues energization, is still a major hurdle to the widespread use of NCs in commercial applications. In particular, the reactivity of red-emitting perovskites to environmental surroundings is more sensitive than that of their green counterparts.

Strong Plasmon-Mie Resonance in Si@Pd Core-Ω Shell Nanocavity.

The surface plasmon resonance (SPR) and localized surface plasmon resonance (LSPR) can be used to enhance the generation of the hot electrons in plasmon metal nanocavity. In this paper, Pd nanomembrane (NMB) is sputtered on the surface of Si nanosphere (NS) on glass substrate to form the Si@Pd core-Ω shell nanocavity. A plasmon-Mie resonance is induced in the nanocavity by coupling the plasmon resonance with the Mie resonance to control the optical property of Si NS.

Resonance Coupling in Si@WSCore-Ω Shell Nanostructure.

Realizing strong laser-matter interaction in a heterostructure consisting of two-dimensional transition metal dichalcogenides (TMDCs) and an optical nanocavity is a potential strategy for novel photonic devices. In this paper, two core-Ω shell nanostructures, Si@WS core-Ω shell nanostructure on glass/Si substrates, are briefly introduced. A strong laser-matter interaction occurred in the Si@WS core-Ω shell nanostructure when it was excited by femtosecond (fs) laser in the near-infrared-1 region (NIR-1, 650 nm-950 nm), resulting in a resonance coupling between the electric dipole resonance (EDR) of the Si nanosphere (NS) and the exciton resonance of the WS nanomembrane (NMB).

Numerical investigation of localization in two-dimensional quasiperiodic mosaic lattice.

A one-dimensional lattice model with mosaic quasiperiodic potential is found to exhibit interesting localization properties, e.g. clear mobility edges (Wang2020196604).

Polarization-resolved and helicity-resolved Raman spectra of monolayer XP (X = Ge and In).

Monolayer XP (X = Ge, In) is a theoretically predicted two-dimensional (2D) material with fascinating adsorption efficiency, foreshadowing its potential applications in the photovoltaic and optoelectronic communities. To achieve a comprehensive understanding of its optical properties and to further boost quickly identifying its specific applications, in this paper we systematically investigated the polarization-resolved and helicity-resolved Raman spectra excited by two commonly used laser lines (532 nm and 633 nm) through density functional theory. The dynamical stability of monolayer XP is demonstrated by phonon dispersion.

Charge Carrier Recombination Dynamics in MAPb(BrCl) Single Crystals.

Understanding carrier recombination processes in MAPb(BrCl) crystals is essential for their photoelectrical applications. In this work, carrier recombination dynamics in MAPb(BrCl) single crystals were studied by steady-state photoluminescence (PL), time-resolved photoluminescence (TRPL), and time-resolved microwave photoconductivity (TRMC). By comparing TRPL and TRMC, we find TRPL of MAPb(BrCl) ( < 0.

Photoinduced Polaron Formation in a Polymerized Electron-Acceptor Semiconductor.

Polymerized small molecular acceptor (PSMA) based all-polymer solar cells (all-PSC) have achieved power conversion efficiencies (PCE) over 16%, and the PSMA is considered to hold great promise for further improving the performance of all-PSC. Yet, in comparison with that of the polymer donor, the photophysics of a polymerized acceptor remains poorly understood. Herein, the excited state dynamics in a polymerized acceptor PZT810 was comprehensively investigated under various pump intensities and photon energies.

Charge Photogeneration and Recombination in Fluorine-Substituted Polymer Solar Cells.

In this contribution, we studied the effect of fluorine substitution on photogenerated charge generation, transport, and recombination in polymer solar cells. Two conjugated polymer materials, PBDTTT-E (fluorine free) and PTB7 (one fluorine substitution), were compared thoroughly. Meanwhile, various characterization techniques, including atomic force microscopy, steady-state spectroscopy, transient absorption spectroscopy, spectroelectrochemistry, and electrical measurements, were employed to analyse the correlation between molecular structure and device performance.

Theoretical assessment of Raman spectra on MXene TiC: from monolayer to bilayer.

The structural, vibrational and Raman spectra properties of monolayer and bilayer TiC excited by two commonly used laser lines (532 nm and 633 nm) are investigated by first principles calculations to establish a correlation among layer stacks and optical features for two-dimensional MXenes. The stability of the monolayer and the energetically preferable stacking configuration are demonstrated by phonon dispersion. The monolayer and bilayer TiC systems are found to exhibit different point group symmetries and thereby the Raman properties due to the symmetry breaking of the bilayer structure caused by interlayer van der Waals interactions.