Advanced Optical Materials最新文献

2D Dion-Jacobson (DJ) ferroelectric perovskites show outstanding potential for self-powered X-ray detection due to their high bulk resistivity and robust bulk photovoltaic effect (BPVE). Existing literature generally considered distortion of inorganic octahedral cages as detrimental to their photoelectric properties. Herein, this study demonstrates that larger distortion may be designed to attain more stable structures by promoting stronger hydrogen bonding between the inorganic cage and the organic chains, thus effectively suppressing ion migration. Furthermore, lattice distortion triggers the formation of electric dipoles, inducing spontaneous polarity and thereby augmenting the collection efficiency of photo generated charges. Leveraging the out-of-plane ferroelectric polarity of 4AMPPbI₄, a self-powered X-ray detection is pioneered with the vertical structure, offering superior integration and assembly for practical applications compared to lateral-structures. The resulting X-ray detector exhibits exceptional performance, featuring a low noise current of 7.53 pA and an impressive self-powered sensitivity of 234.74 µC Gy_air⁻¹ cm⁻² at zero bias, surpassing all 2D self-powered detectors in detection limits (6.6 nGy_air s⁻¹). Moreover, the device demonstrates commendable storage stability, retaining 95.9% initial sensitivity over 60 days under a 50V bias and 94.7% over 30 days in self-powered mode.

R. Chang, Q. Yin, L. Han, et al.: Efficient and Low-Noise Extended Shortwave Photodiodes Based on PbSe Colloidal Quantum Dots with Wide Depletion Width. Adv. Optical Mater. 13, 2502242 (2025). https://doi.org/10.1002/adom.202502242

In the above article, the schematic diagram of the device structure shown in Figure 2a didn’t correctly show the Ag doping in PbS-EDT layer. We replaced the schematic diagram to display the Ag doping. The changes are as below:

Redrawn Figure:

Original Figure:

We apologize for this error.

Ferroelectric nematic fluids are promising materials for tunable nonlinear photonics, with applications ranging from second harmonic generation to sources of entangled photons. However, the few reported values of second-order susceptibilities vary widely depending on the molecular architecture. Here, we systematically measure second-order NLO susceptibilities of five different materials that exhibit the ferroelectric nematic phase, as well as the more recently discovered layered smectic A ferroelectric phase. The materials investigated include archetypal molecular architectures as well as mixtures showing room-temperature ferroelectric phases. The measured values, which range from 0.3 to 20 pm V⁻¹, are here reasonably predicted by combining calculations of molecular-level hyperpolarizabilities and a simple nematic potential, highlighting the opportunities of modelling-assisted design for enhanced NLO ferroelectric fluids.

Recent investigations into the bandgap evolution of hybrid perovskites under hydrostatic pressure have primarily focused on the room-temperature cubic phase of methylammonium lead bromide (MAPbBr₃), leaving its low-temperature behavior largely unexplored. In this work, the pressure response of MAPbBr₃ single crystals is investigated over a broad temperature range using photoluminescence (PL), cathodoluminescence (CL), and density functional theory (DFT) calculations. Hydrostatic pressure is shown to modify the electronic structure of MAPbBr₃ across cubic (280 K, 260 K), tetragonal (210, 170 K), and orthorhombic (120, 80 K) phases, quantified via the bandgap pressure coefficient (α). The experimentally obtained α values are: α_280K,260K = −47 ± 3 meV GPa⁻¹, α_210K,170K = −48 ± 3 meV GPa⁻¹, α_120K,80K = −90 ± 3 meV GPa⁻¹. The pressure coefficient calculated theoretically within the DFT calculations at zero temperature is −100 ± 2 meV GPa⁻¹. The increasingly negative α values observed with decreasing temperature reflect the suppression of inorganic cage phonon activity and the reduced orientational freedom of MA⁺ cations. These findings highlight the crucial influence of molecular dynamics and the interplay between organic and inorganic sublattices in governing the pressure response of hybrid perovskites across different structural phases.

Magnetic interfacial exchange bias, as a key control method for spintronic devices, remains unclear in terms of its ultrafast dynamic behavior and its role in regulating spintronic terahertz emissions. In this work, femtosecond optical pulses are used to excite ferromagnetic/antiferromagnetic bilayer films with interfacial exchange bias, and a significant modulation phenomenon of terahertz emission is observed by comparing samples with different magnetization pinning states induced by exchange bias. Through the measurement of dynamic hysteresis loops under femtosecond optical pulse excitation, it is confirmed that the optical pulse can rapidly break and then recover the exchange bias within the picosecond time scale. This transient reconstruction process of exchange bias effectively enhances the ultrafast spin precession signal at ≈2 THz, while suppressing the ultrafast demagnetization-related signal at ≈0.77 THz. By exploiting the difference in flip symmetry of the samples, this is found that the photo-introduced magnetization dynamics process dominated the modulation effect of the exchange bias on the two frequency bands. These results reveal that picosecond-scale transient exchange bias can regulate both the frequency content and coherence of spintronic terahertz emission, offering a pathway toward tunable terahertz spintronic sources.

Mechanochromic materials usually exhibit observable changes in photophysical properties under force stimulation, and have attracted increasing attention due to their wide range of potential applications. Herein, the study designs and synthesizes mechanochromic microcapsules that harness mechanically triggered release to precisely modulate the excited-state conformation of vibration-induced emission (VIE) fluorophores. Double-shelled polyurethane/poly(urea-formaldehyde) microcapsules encapsulating hexyl-acetate solution of VIE molecules are fabricated via in situ emulsification condensation polymerization. The microcapsules can protect VIE molecules from external environmental interference and be embedded with various polymers without chemical modification to build mechanochromic materials. Mechanical activation triggers instantaneous rupture of the microcapsules; the vibrational limitation of VIE molecules due to solvent evaporation provides detectable fluorescent color changes, making it possible to monitor polymer damage and deformation through naked-eye vision. This microcapsule-based mechanochromic material exhibited exceptional sensing performance under complex external forces, offering new mechanistic insights for the design of intelligent mechanoresponsive systems.

Dynamic control of light, and in particular beam steering, is pivotal in various optical applications, including telecommunications, LiDAR, and biomedical imaging. Traditional approaches achieve this by interfacing a tunable modulating device with an external light source, facing challenges in achieving compact devices. Here, a dynamic photoluminescence (PL) modulating device is introduced, with which the properties of light directly emitted by a quasi-2D perovskite (in particular, its directionality and polarization) can be modified continuously and over a large range. The device is based on a liquid-crystal-tunable Fabry-Perot (FP) nanocavity and uses the FP energy-momentum dispersion and spin-orbit coupling between the excitons and the cavity modes to enable this dynamic control over the emitted radiation. With this device, electrically-controlled, continuous, and variable emission angles are achieved up to a maximum of 28°, as well as manipulation of the PL polarization state, enabling both the creation of polarization gradients and the achievement of angle-specific polarization conversion. Moreover, due to its resonant character, a threefold increase in the emission intensity is observed. This approach leverages the unique properties of actively tunable birefringent nanocavities to improve emission directivity, angle tunability, and polarization control, presenting a promising solution for next-generation, deeply integrated beam steering devices.

Over the past few decades, organic light-emitting diodes (OLEDs) have demonstrated compelling technological advantages due to their ability to directly convert electrons into photons without requiring backlighting, thereby offering self-emissive surfaces, ultrathin device profiles, compatibility with flexible substrates, high luminance, and exceptional contrast ratios (achieving true black). Today, OLEDs dominate the market for small-scale displays such as smartphones and laptops. Propelled by the burgeoning ubiquity of the Internet of Things, OLEDs are poised to experience an exponential upsurge in prospective exigency. However, conventional thermal evaporation techniques face challenges in achieving uniform large-area OLED fabrication, rendering mass production costly and complex—a persistent drawback hindering OLEDs from becoming the undisputed market leader. Amidst this milieu, inkjet printing (IJP) has magnetized considerable scholarly and commercial traction across the panoply of fabrication modalities, crystallizing as the pre-eminent candidate for scalable, large-area OLED manufacturing. This technique boasts non-contact processing, high material utilization, and compatibility with roll-to-roll manufacturing. In this review, the critical parameters governing ink formulation are delineated and provide an overview of prevailing OLED device architectures. Subsequently, recent advancements are consolidate in inkjet-printed OLED layers, culminating in a circumspect prognosis of the extant impediments and the prospective trajectory toward wholly inkjet-patterned OLED architectures.

Light-matter interactions are powerful tools that seamlessly allow both functionalities of sizeable bandgap modulation and non-invasive spectroscopy. While the border between modulation and detection is often assumed to be sharp and well-defined, there are experiments where the boundaries fade. Here, the interplay between bandgap modulation and non-invasive spectroscopy is measured and explained in the case of resonant perturbative nonlinear optics in an atomically thin direct gap semiconductor.A clear deviation from the typical quadratic power scaling of second-harmonic generation near an exciton resonance is reported, and this unusual result is explained based on all-optical modulation driven by the intensity-dependent optical Stark and Bloch–Siegert shifts in the ±K valleys of the Brillouin zone. The experimental results are corroborated by analytical and numerical analysis based on the semiconductor Bloch equations, from which the resonant transition dipole moments and dephasing times of the sample are extracted. These findings redefine the meaning of perturbative nonlinear optics by revealing how coherent light-matter interactions can modify the band structure of a crystal, even in the weak-field regime. Furthermore, the results strengthen the understanding of ultrafast all-optical control of electronic states in 2D materials, with potential applications in valleytronics, Floquet engineering, and light-wave electronics.

Constructing functionalized interlayers in buried surface of perovskite solar cells (PSCs) is highly desirable but yet challenging due to the inevitable erosion of high-polarity DMF (i.e., N,N-dimethylformamide) solvent during the solution processing of the perovskite layer. In this work, two novel perylene diimide-octyl polyhedral oligomeric silsesquioxane (PDI-OPOSS)-based polymers are designed and synthesized via ring-opening metathesis polymerization (ROMP), as stable and multifunctional interlayer in PSCs. The OPOSS units are attached to the side chain of the polynorbornene skeleton through a soft (P1) or rigid (P2) spacer. The introduction of the OPOSS units enhances the polymers’ solubility in low-polarity organic solvents, resulting in excellent film-forming ability and strong hydrophobicity. Meanwhile, the PDI groups tethered to the polynorbornene backbone provide an electron transport path, crucial for its application as an interlayer between the perovskite active layer and charge-transport layer in PSCs. These newly developed PDI-OPOSS polymers efficiently tailor energy level alignments of buried surface and enhance charge transport within PSCs, leading to an impressive efficiency of 23.06% achieved by the P2-modified PSC. This work provides new insights to significantly potential applications of semi-conducting interlayer materials in perovskite photovoltaics.