Advanced Optical Materials最新文献

Grating Coupled Surface Plasmon Resonance Technology

The Review by Vivek Pachauri and co-workers (see article number 2401862) delves into the core principles, manufacturing processes, and cutting-edge developments in Grating-coupled Surface Plasmon Resonance (GCSPR). Enhancements in nanofabrication techniques, including roll-to-roll nanoimprint technology, have made scalable and precise on-chip sensor platforms feasible. Innovative experimental setups, incorporation of novel materials, and machine learning-driven data analysis are elevating sensitivity and standardization, critical for clinical adoption, and aligning with the latest IoT healthcare trends. [Image credit: Hocine Bahri and Divagar Murugan, RWTH Aachen.]

Aqueous Afterglow Dispersion Enabling Mercury Ion Sensing

This cover image illustrates the application of an aqueous-phase phosphorescent probe for the detection of heavy metal ions. The carbon dots (CDs)@hydrogen-bonded organic frameworks (HOFs) composite material functions as the energy donor, while a rhodamine B derivative acts as metal ions probe and the energy acceptor, facilitating the phosphorescent detection of mercury ions in aqueous environments via a Förster energy transfer mechanism. This approach highlights the potential of aqueous phosphorescent materials for environmental monitoring and analytical applications. For further details, see article number 2401509 by Guangqiang Yin, Tao Chen, Zhixiong Cai, and co-workers.

Localized Thermal Conductivity Measurement

The cover image shows a hybrid diamond–silicon pillar micro-sensor with a decoupled all-optical temperature control and readout method for localized thermal conductivity measurement in hydrogels. The decoupling of the heating and sensing lasers can minimize the crosstalk between them. Thermal conductivity is measured using a steady-state thermometry strategy based on the laser heating effect. This novel sensor and sensing strategy demonstrate significant advancements in micro-scale thermometry. For further details, see article number 2401232 by Zhiqin Chu and co-workers.

Lead halide perovskites exhibit superior properties compared to classical III–V semiconductor quantum wells for room-temperature polaritonic applications, particularly owing to the significant crystalline anisotropy. This anisotropy results in a sizeable split in condensate energy, which can profoundly influence polariton interactions and spin relaxation pathways. Besides, trapped exciton-polariton (TEP) exhibits a quantized energy landscape, which is essential for modulating polaritonic logical circuits. Herein, spin-orbit coupled TEP lasing is demonstrated in birefringent perovskite. Cascade condensate processes between orthogonally polarized polariton branches happen considering the dominance of reservoir exciton–polariton or polariton–polariton scattering within each stage. Such condensation adequately is verified via the input-output “S” curve, the narrowed linewidth, the energy blueshift, and the real space spatial coherence of the orthogonally polarized modes. This trapped anisotropic condensate holds great promise for room-temperature polaritonic and spintronics.

Conventional fluorescent WOLEDs generate white light by incomplete energy transfer but face challenges in precisely controlling energy transfer and improving device efficiency due to the maximal utilization of 25% singlet excitons. In this study, two newly developed excited-state intramolecular proton transfer (ESIPT) fluorophores emit orange and white light. These fluorophores utilize excitons efficiently (70–88%) via high-level reverse intersystem crossing (hRISC) exclusively in the keto form and in both isomers (enol/keto), respectively. The white emitter, with comparable dual emissions, enables the fabrication of color-stable cold-white single-emitter OLED with a CRI of 74 and maximum external quantum efficiency (EQE) of up to 5.60%. The orange emitter, when combined with a sky-blue TADF fluorophore, creates non-energy-transferred single-emitting-layer (SML) high-performance cold- and pure-white WOLEDs with CIE coordinates of (0.26, 0.35) and (0.32, 0.32), and maximum EQEs of 13.34% and 9.66%, respectively. Importantly, these complementary-color WOLEDs demonstrate high reproducibility, offering advantages for industrial batch fabrication. Thus, this research presents a route to achieve cost-effective mass production of simple-structured and high-efficiency WOLEDs.

Benefiting from the potential application as a single component white light source, the broadband self-trapped excitons (STEs) emission in low-dimensional metal halides has attracted wide attention. However, such broadband STE emission in metal thio- and seleno-phosphates is scarce, and the formation mechanism is ambiguous. Herein, the broadband dual-mode (red and near-infrared) light emission and their linear polarization in orthorhombic Cu₃PS₃Se crystals are reported. The absorption and photoluminescence (PL) spectra show a large Stokes shift of 0.43/0.76 eV and a broad emission wavelength range of ≈200 nm, exhibiting the significant STEs feature. Transient absorption spectroscopy (TAS) reveals a broad positive photo-induced absorption, further proving the formation of STE states. These STEs exhibit a highly linear polarized emission behavior with a degree of polarization up to 0.51. According to the excitation angles dependent polarized PL and Raman spectroscopy measurements, it is assigned that both the anisotropic optical absorption and electron-phonon interaction contribute to the STEs emission polarization in Cu₃PS₃Se. These findings not only extend the STEs from metal halides to metal thio/seleno-phosphates but also offer the potential prospects for novel optical polarizers, polarization-sensitive photodetectors, optical and optoelectronic synaptic devices application of anisotropic STEs emission.

Tailorability of a medium's optical properties, specifically refractive index and dispersion, is key to enabling compact optical designs. Chalcogenide glasses (ChGs) are widely used for infrared (IR) imaging applications, and the development of gradient refractive index (GRIN) optics. This work extends efforts to create and characterize 3D GRIN profiles in bulk multi-component Ge-As-Pb-Se (GAP-Se) ChGs through spatially selective conversion of commercial glass to glass ceramic. This work extends prior efforts on bulk and film lab-scale glass media, to that of a commercially produced material with improved optical homogeneity. Laser-induced crystallization upon heat treatment results in the formation of high index Pb-containing crystals that contribute to an increase in the nanocomposite's resulting effective refractive index, n_eff. The material's induced crystallinity imparted via laser exposure and heat treatment using metrology tools such as refractometry, X-ray diffraction, FTIR, and TEM are studied. The resulting material response is quantified which is shown to be modulated via laser dose in both lateral and for the first time, axial directions enabling the first demonstration of a true, 3D GRIN profile. By comparing these outcomes to prior radial GRIN structures, the promise of these media as candidate materials for infrared systems.

Electrically Controllable Dual-State Förster Energy Resonance Transfer

An electrically controllable long-lived room-temperature phosphorescence (RTP) switch was developed by Yu-Mo Zhang, Tingting Lin, and co-workers (see article number 2402313). The left doll symbolizes an organic phosphorescent material. The right doll symbolizes a spectrally matched dye, and the flower below symbolizes an electro-acid. Upon wireless electrical stimulation, the electro-acid undergoes redox-induced conformational switching of the dyes, which in turn undergoes a dual-state Förster energy resonance transfer process with RTP, exhibiting multiple switching properties.