Nanoscale Research Letters

Broadband high absorption of long-wavelength infrared light for rough submicron active material films is quite challenging to achieve. Unlike conventional infrared detection units, with over three-layer complex structures, a three-layer metamaterial with mercury cadmium telluride (MCT) film sandwiched between an Au cuboid array and Au mirror is studied through theory and simulations. The results show that propagated/localized surface plasmon resonance simultaneously contribute to broadband absorption under the TM wave of the absorber, while the Fabry-Perot (FP) cavity resonance causes absorption of the TE wave...

Silicon sub-bandgap near-infrared (NIR) (λ > 1100 nm) photovoltaic (PV) response by plasmon-enhanced internal photoemission was investigated. The Si sub-bandgap NIR PV response, which remains unexploited in Schottky junction-like solar cell device, was examined using nanometer sized Au/Al2 O3 /n-Si junction arrays. This kind of metal-insulator-semiconductor structure was similar in functionality to Schottky junction in NIR absorption, photo-induced charge separation and collection...

The detection of pollutant and toxic gases has attracted extensive attention due to the growing environmental issues. In the present investigation, free-based tetraphenyl porphyrin (TPP) and iron tetraphenyl porphyrin (FeTPP) are used to functionalize thermally reduced graphene oxide (rGO) and further used for the detection of carbon monoxide (CO). TPP and FeTPP functionalized rGO (FeTPP@rGO) sensors are fabricated on a glass substrate with thermally coated copper electrodes. The materials are characterized with X-ray diffraction (XRD), Fourier transforms infrared (FTIR) spectroscopy, Raman spectroscopy, UV-visible spectroscopy, atomic force microscopy, scanning electron microscopy, and energy dispersive spectroscopy...

Strong light-matter interaction plays a central role in realizing quantum photonic technologies. The entanglement state, which results from the hybridization of excitons and cavity photons, forms the foundation of quantum information science. In this work, an entanglement state is achieved by manipulating the mode coupling between surface lattice resonance and quantum emitter into the strong coupling regime. At the same time, a Rabi splitting of 40 meV is observed. A full quantum model based on the Heisenberg picture is used to describe this unclassical phenomenon, and it perfectly explains the interaction and dissipation process...

InAs quantum dashes (Qdash) engineered to emit near 2 μm are envisioned to be promising quantum emitters for next-generation technologies in sensing and communications. In this study, we explore the effect of punctuated growth (PG) on the structure and optical properties of InP-based InAs Qdashes emitting near the 2-μm wavelength. Morphological analysis revealed that PG led to an improvement in in-plane size uniformity and increases in average height and height distribution. A 2 × boost in photoluminescence intensity was observed, which we attribute to improved lateral dimensions and structural stabilization...

Carbon dots (CDs) or CDs/polymer composites have been applied in numerous fields. Here, novel CDs were synthesized by carbonization of egg yolk, and characterized by TEM, FTIR, XPS and photoluminescence spectra. The CDs were found to be approximate sphere in shape with an average size of 4.46 ± 1.17 nm, and emitted bright blue photoluminescence under UV irradiation. The photoluminescence of CDs was found selectively quenched by Fe3+ in a linear manner in the range of 0.05-0.45 mM, meaning they could be applied for Fe3+ detection in solution...

Though light-emitting diodes (LEDs) combined with various color conversion techniques have been widely explored for VLC (visible light communication), E-O (electro-optical) frequency responses of devices with quantum dots (QDs) embedded within the nanoholes have rarely been addressed. Here we propose LEDs with embedded photonic crystal (PhC) nanohole patterns and green light QDs for studying small-signal E-O frequency bandwidths and large signal on-off keying E-O responses. We observe that the E-O modulation quality of PhC LEDs with QDs is better than a conventional LED with QDs when the overall blue mixed with green light output signal is considered...

The influence of self-assembled short-period superlattices (SPSLs) on the structural and optical properties of InGaN/GaN nanowires (NWs) grown by PAMBE on Si (111) was investigated by STEM, EDXS, µ-PL analysis and k·p simulations. STEM analysis on single NWs indicates that in most of the studied nanostructures, SPSLs self-assemble during growth. The SPSLs display short-range ordering of In-rich and In-poor Inx Ga1-x N regions with a period of 2-3 nm that are covered by a GaN shell and that transition to a more homogenous Inx Ga1-x N core...

The flexible pressure sensor is expected to be applied in the new generation of sports wearable electronic devices. Developing flexible pressure sensors with a wide linear range and great sensitivity, however, remains a significant barrier. In this work, we propose a hybrid conductive elastomeric film oxide-based material with a concave-shape micro-patterned array (P-HCF) on the surface that sustainably shows the necessary sensing qualities. To enhance sensing range and sensitivity, one-dimensional carbon fibers and two-dimensional MXene are incorporated into the polydimethylsiloxane matrix to form a three-dimensional conductive network...

No abstract text is available yet for this article.

Piezoelectric microelectromechanical system (piezo-MEMS)-based mass sensors including the piezoelectric microcantilevers, surface acoustic waves (SAW), quartz crystal microbalance (QCM), piezoelectric micromachined ultrasonic transducer (PMUT), and film bulk acoustic wave resonators (FBAR) are highlighted as suitable candidates for highly sensitive gas detection application. This paper presents the piezo-MEMS gas sensors' characteristics such as their miniaturized structure, the capability of integration with readout circuit, and fabrication feasibility using multiuser technologies...

The need for high-performance gas sensors is driven by concerns over indoor and outdoor air quality, and industrial gas leaks. Due to their structural diversity, vast surface area, and geometric tunability, metal oxides show significant potential for the development of gas sensing systems. Despite the fact that several previous reports have successfully acquired a suitable response to various types of target gases, it remains difficult to maintain the reliability of metal oxide-based gas sensors. In particular, the degradation of the sensor platform under repetitive operation, such as off-state stress (OSS) causes significant reliability issues...

The preparation of two-dimensional magnetic materials is a key process to their applications and the study of their structure and morphology plays an important role in the growth of high-quality thin films. Here, the growth, structure, and morphology of Cr1+δ Te2 films grown by molecular beam epitaxy on mica with variations of Te/Cr flux ratio, growth temperature, and film thickness have been systematically investigated by scanning tunneling microscopy, reflection high-energy electron diffraction, scanning electron microscope, and X-ray photoelectron spectroscopy...

In the extreme ultraviolet lithography system, EUV-induced hydrogen plasma charging effect is observed by in situ embedded micro-detector array. The 4k-pixel on-wafer array can detect and store the distributions of H2 plasma in each in-pixel floating gate for non-destructive off-line read. The local uniformity of H2 plasma intensity extracted by the threshold voltages on an array and its distributions across a wafer by the average bit cell current of MDAs provide insights into the detailed conditions inside advanced EUV lithography chambers...

Metformin (MET) is an anti-diabetic drug employed as the first-line therapy for patients of type II diabetes mellitus (T2DM). Overdosage of drugs leads to severe outcomes, and its monitoring in biofluids is vital. The present study develops cobalt-doped yttrium iron garnets and employs them as an electroactive material immobilized on a glassy carbon electrode (GCE) for the sensitive and selective detection of metformin via electroanalytical techniques. The fabrication procedure via the sol-gel method is facile and gives a good yield of nanoparticles...

This study theoretically demonstrated the oxygen vacancy (VO 2+ )-based modulation of a tunneling junction memristor (TJM) with a high and tunable tunneling electroresistance (TER) ratio. The tunneling barrier height and width are modulated by the VO 2+ -related dipoles, and the ON and OFF-state of the device are achieved by the accumulation of VO 2+ and negative charges near the semiconductor electrode, respectively. Furthemore, the TER ratio of TJMs can be tuned by varying the density of the ion dipoles (Ndipole ), thicknesses of ferroelectric-like film (TFE ) and SiO2 (Tox ), doping concentration (Nd ) of the semiconductor electrode, and the workfunction of the top electrode (TE)...

We fabricated an alcohol detector based on (PEA)2 (CH3 NH3 )3 Sb2 Br9 ((PEA)2 MA3 Sb2 Br9 ) lead-free perovskite-like films. The XRD pattern revealed that the (PEA)2 MA3 Sb2 Br9 lead-free perovskite-like films exhibited a quasi-2D structure. The optimal current response ratios are 74 and 84 for 5 and 15% alcohol solutions, respectively. When the amount of PEABr decreases in the films, the conductivity of the sample in ambient alcohol with a high alcohol concentration solution increases. The alcohol was dissolved into water and carbon dioxide due to the catalyst effect of the quasi-2D (PEA)2 MA3 Sb2 Br9 thin film...

Recent years have witnessed an increased interest in the development of nanoparticles (NPs) owing to their potential use in a wide variety of biomedical applications, including drug delivery, imaging agents, gene therapy, and vaccines, where recently, lipid nanoparticle mRNA-based vaccines were developed to prevent SARS-CoV-2 causing COVID-19. NPs typically fall into two broad categories: organic and inorganic. Organic NPs mainly include lipid-based and polymer-based nanoparticles, such as liposomes, solid lipid nanoparticles, polymersomes, dendrimers, and polymer micelles...

Recently, flexible sensors with high sensitivity have been applied in wearable sports sensing field. Here, we reported a flexible and sensitive capacitive pressure sensor based on nylon textile and polyvinylidene fluoride (PVDF) dielectric film. From the experimental results, the sensor has an extremely high sensitivity of 33.5 kPa-1 , a low detection limit of 0.84 Pa, a quick response time of 27 ms. Moreover, the pressure sensor shows excellent reliability under over 100,000 working cycles. With their superior overall performance, capacitive sensors have effectively proved their enormous potential for basketball motion monitoring...

Perovskites are the key enabler materials for the solar cell applications in the achievement of high performance and low production costs. In this article, the structural, mechanical, electronic, and optical properties of rubidium-based cubic nature perovskite LiHfO3 and LiZnO3 are investigated. These properties are investigated using density-functional theory with the aid of CASTEP software by introducing ultrasoft pseudo-potential plane-wave (USPPPW) and GG-approximation-PB-Ernzerhof exchange-correlation functionals...