Two-dimensional metallic broadband absorbers on a SiO(2)/Ag/Si substrate were experimentally studied. The absorptivity of such structure can be increased by tailoring the ratio of disk size to the unit cell area. The metallic disk exhibits a localized surface plasmon polariton (LSPP) mode for both TE and TM polarizations. A broadband thermal emitter can be realized because the LSPP mode is independent of the periodicities. By manipulating the ratios and disk sizes, a high-performance, wide-angle, polarization-independent dual band absorber was experimentally achieved. The results demonstrated a substantial flexibility in absorber designs for applications in thermal photovoltaics, sensors, and camouflage.

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Monolayer transition metal dichalcogenides (TMDs), direct bandgap materials with an atomically thin nature, are promising materials for electronics and photonics, especially at highly scaled lateral dimensions. However, the characteristically low total absorption of photons in the monolayer TMD has become a challenge in the access to and realization of monolayer TMDbased high-performance optoelectronic functionalities and devices. Here, we demonstrate gate-tunable plasmonic phototransistors (photoFETs) that consist of monolayer molybdenum disulfide (MoS 2 ) photoFETs integrated with the two-dimensional plasmonic crystals. The plasmonic photoFET has an ultrahigh photoresponsivity of 2.7 × 10 4 AW −1 , achieving a 7.2-fold enhancement in the photocurrent compared to pristine photoFETs. This benefits predominately from the combination of the enhancement of the photon-absorption-rate via the strongly localized-electromagnetic-field and the gate-tunable plasmon-induced photocarriergeneration-rate in the monolayer MoS 2 . These results demonstrate a systematic methodology for designing ultrathin plasmonenhanced photodetectors based on monolayer TMDs for next-generation ultracompact optoelectronic devices in the trans-Moore era.

The 2-D transition metal dichalcogenide (TMD) semiconductors, has received great attention due to its excellent optical and electronic properties and potential applications in field-effect transistors, light emitting and sensing devices. Recently surface plasmon enhanced photoluminescence (PL) of the weak 2-D TMD atomic layers was developed to realize the potential optoelectronic devices. However, we noticed that the enhancement would not increase monotonically with increasing of metal plasmonic objects and the emission drop after the certain coverage. This study presents the optimized PL enhancement of a monolayer MoS2 in the presence of gold (Au) nanorods. A localized surface plasmon wave of Au nanorods that generated around the monolayer MoS2 can provide resonance wavelength overlapping with that of the MoS2 gain spectrum. These spatial and spectral overlapping between the localized surface plasmon polariton waves and that from MoS2 emission drastically enhanced the light emission from the MoS2 monolayer. We gave a simple model and physical interpretations to explain the phenomena. The plasmonic Au nanostructures approach provides a valuable avenue to enhancing the emitting efficiency of the 2-D nano-materials and their devices for the future optoelectronic devices and systems.

Efficient Auger relaxation in colloidal quantum dots (QDs) plays a crucial role in determining single-QD fluorescence behavior, for example, leading to fluorescence blinking and pure single-photon emission. Here, we demonstrate that when single-QD emission is coupled to a plasmonic gap mode, the fluorescence behavior is no longer dictated by nonradiative Auger relaxation, instead by radiative decay processes. In this case, annoying blinking can be largely suppressed accompanied by fluorescence enhancement. Moreover, the radiative decay rates for both exciton (X) and biexciton (BX) can be enhanced simultaneously owing to the broadband nature of a plasmonic gap mode with large Purcell effect. As a result, the BX quantum yields can be enhanced as high as that of single X emission which is derived from photon correlation measurement. This demonstration paves the way toward generating correlated photon pairs through BX–X cascade emission at room temperature based on cost-effective colloidal QDs.

The small sized, flexible, high-performed and bio-compatible sensing devices are the critical elements to realize the bio-related detection or on-site health monitoring systems. In this work, the flexible localized surface plasmon resonance (LSPR) bio-sensors were demonstrated by integrating the metal–insulator–metal (MIM) nanodisks with bio-compatible polydimethylsiloxane (PDMS) substrate. The different geometries of MIM nanodisk sensors were investigated and optimized to enhance the spatial overlap of the LSPR waves with the environment, which lead to a high sensitivity of 1500 nm/RIU. The omni-directional characteristics of LSPR resonances were beneficial for maintaining the device sensitivity stable under various bending curvatures. Furthermore, the flexible MIM nanodisk LSPR sensor was applied to detect A549 cancer cells in PBS+ solution. The absorption peak of the MIM-disk LSPR sensor obviously redshift to easily distinguish between the phosphate buffered saline (PBS+) solution with A549 cancer cells and without cells. Therefore, the flexible MIM nanodisk LSPR sensor is suitable to develop on-chip microfluidic biosensors for detection of cancer cells on nonplanar surfaces.

NAFLD and SUA levels were strongly and independently associated in this nationally representative sample of men and women after adjustment for multiple factors.

2D ternary semiconductor single crystals, an emerging class of new materials, have attracted significant interest recently owing to their great potential for academic interest and practical application. In addition to other types of metal dichalcogenides, 2D tin dichalcogenides are also important layered compounds with similar capabilities. Yet, multi‐elemental single crystals enable to assist multiple degrees of freedom for dominant physical properties via ratio alteration. This study reports the growth of single crystals Se‐doped SnS2 or SnSSe alloys, and demonstrates their capability for the fabrication of phototransistors with high performance. Based on exfoliation from bulk high quality single crystals, this study establishes the characteristics of few‐layered SnSSe in structural, optical, and electrical properties. Moreover, few‐layered SnSSe phototransistors are fabricated on both rigid (SiO2/Si) and versatile polyethylene terephthalate substrates and their optoelectronic properties are examined. SnSSe as a phototransistor is demonstrated to exhibit a high photoresponsivity of about 6000 A W−1 with ultra‐high photogain ≈8.8 × 105, fast response time ≈9 ms, and specific detectivity (D*) ≈8.2 × 1012 J. These unique features are much higher than those of recently published phototransistors configured with other few‐layered 2D single crystals, making ultrathin SnSSe a highly qualified candidate for next‐generation optoelectronic applications.