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Recent advancements in wireless communication have markedly increased data throughput and decreased latency in progressing toward sixth‐generation (6G) networks, wherein the terahertz (THz) waveband offers significant potential. However, conventional THz sensors often suffer from high noise, low responsivity, and low spectrum efficiency, limiting their effectiveness for THz applications. Here, to address these challenges, a magnetic‐enhanced frequency‐selective is developed THz sensor by depositing an Au‐enhanced active layer of MoTe2 on a designed 3D printing high‐depth micro‐helical stepped structure. This sensor, featuring four characteristic frequency points and an effective area of 107.12 mm2, demonstrated noticeable improvements under a 0.145 mT magnetic field at 0.1 THz: optical responsivity improved by 413.23% (from 3.32 to 17.03 MV W−1), noise equivalent power decreased by 80.51% (from 49.16 to 9.58 pW Hz−1/2), and the detectivity reached 3.30 × 1010 cm·Hz1/2·W−1. This work highlights the potential of integrating 3D microstructures with novel topological materials for practical 6G communication. [ABSTRACT FROM AUTHOR]

Near ultraviolet (NUV) organic light‐emitting diodes (OLEDs) have great advantages in the field of light excitation sources, chemical and biological sensors, etc. However, the molecular design of NUV emitters still faces the challenges of spectral broadening and red‐shift. In this study, attaching weak oxygen‐bridged triarylboron acceptor to weak carbazolyl donor is able to address intractable problems by weakening donor–acceptor (D–A) charge transfer. Simultaneously, sterically wrapped and modified oxygen‐bridged triarylboron acceptor by bulk substituents (multiple carbazolyl) can suppress intermolecular π–π stacking through steric hindrance effect. These design strategies are able to obtain short‐wavelength, narrow‐band emission, and great color purity. As a result, carbazolyl derivatives xCz‐BO‐based (x = 2, 3, 4, 5) emitters show EL emission peaks from 406 to 422 nm in the NUV light region and small full‐width at half‐maximums (FWHMs) of 32–41 nm over a wide range of dopant concentrations (10–40 wt.%). The most violet Commission International de I'Eclairage (CIE) color coordinate is (0.16, 0.03). Moreover, 5Cz‐BO can be employed as host for vacuum‐/solution‐processed blue OLEDs and these devices exhibit high performance with EQEs of over 20%. [ABSTRACT FROM AUTHOR]

Photodiode‐type solar‐blind photodetectors (SBPDs) with the self‐powered feature hold great promise for applications in unattended secure communication, flame detection, and missile warning. However, the responsivity of SBPDs is usually limited due to the severe solar‐blind (SB) light extinction in substrates and charge transport layers. Herein, a spectrally selective hole extraction structure (SHE) is proposed for high‐efficiency perovskite SBPDs. The SHE consisting of a tandem Fabry–Perot cavity and energy‐level‐matched hole transport layer endows the device with narrowband absorption in the SB region and optimized charge extraction capability from the CsPbI2Br perovskite. The optimized SHE exhibits a peak transmittance of 27% at 255 nm and a half maximum at full width of 28 nm. Under SB light illumination, the champion device achieves a responsivity of 56.20 mA W−1 and a detectivity (D*) of 2.86 × 1013 Jones, which are the record values among the reported results. The approach demonstrated here paves the way for the optical and electrical design of perovskite photodetectors with spectrally selective detection. [ABSTRACT FROM AUTHOR]

New two‐dimensional (2D) van der Waals materials are emerging, and their optical parameters urgently need to be acquired experimentally. Most of the reported results come from traditional metrologies used in the past for bulk materials. This unavoidably causes controversy regarding the correctness and accuracy of results, as well as the physical model. Surface/interface plasmon polariton waves are sub‐diffraction‐limited and very sensitive to surroundings. Here, 2D van der Waals materials with metal embodied are presented. Surface/interface exciton‐plasmon polaritons come into being with excitons in 2D transition‐metal dichalcogenides (TMDCs), which are physically taken as the boundary conditions with complex optical conductivities at the interfaces. Complex optical conductivities of 2D TMDCs are measured by means of interference behavior of surface/interface polariton waves. The size requirement of 2D van der Waals materials becomes relaxed, and complex optical conductivities can be measured for single‐crystalline WS2 and MoS2 monolayers with small sizes. Furthermore, a remarkable capability is manifested by yielding complex optical conductivity of van der Waals heterostructures. The proposed metrology can apply to other newly developed materials with modified underlying physical models, as well as various types of 2D van der Waals materials. [ABSTRACT FROM AUTHOR]

Semitransparent organic solar cells (STOSCs) hold great promise for applications ranging from building‐integrated photovoltaics to portable electronic devices, yet often challenging over the realization of color tunability. The structural colors generated by microcavity, subwavelength grating, or photonic crystals are highly dependent on the viewing angle, which limits the application of STOSCs in real scenarios. Herein, the spectrally selective substrates consisting of silica spheres‐based amorphous photonic crystals (APCs) are proposed to unify the optical spectra of STOSCs at different viewing angles. By optimizing the periodicity of APCs, STOSCs exhibit viewing‐angle‐independent reflection with colors varying from blue to pink. The synergetic interplay between the reflection of APCs and the absorption of active layer results in the Janus optical effect that the transmitted light is fixed at blue regardless of the reflected color. The STOSCs on flexible plastic retain the stable color even at bending state. These results pave the way for the potential application of colorful solar photovoltaic glass curtains. [ABSTRACT FROM AUTHOR]