We report the observation of optically pumped lasing in ZnO at room temperature. Thin films were grown by plasma-enhanced molecular beam epitaxy on (0001) sapphire substrates. Laser cavities formed cleaving found to lase a threshold excitation intensity 240 kW cm−2. believe these results demonstrate high quality epilayers while clearly demonstrating viability based light emitting devices.

The emission spectrum of high quality ZnO epilayers is studied from room temperature up to 550 K. At and low excitation power a single peak observed which may be identified with the free exciton its energy dependence on temperature. However, when intensities exceed 400 kW cm−2 sharp emerges at lower we attribute exciton-exciton scattering. higher (>800 cm−2) second stimulated even energies: this an electron hole plasma. Similar features are for all temperatures

Abstract Head and neck squamous cell carcinoma is the sixth most common cancer worldwide has high heterogeneity unsatisfactory outcomes. To better characterize tumor progression trajectory, we perform single-cell RNA sequencing of normal tissue, precancerous early-stage, advanced-stage lymph node, recurrent tumors tissue samples. We identify transcriptional development trajectory malignant epithelial cells a tumorigenic subcluster regulated by TFDP1 . Furthermore, find that infiltration...

We investigated the current–voltage characteristics and responsivity of photodiodes fabricated with silicon that was microstructured by use femtosecond-laser pulses in a sulfur-containing atmosphere. The we have broad spectral response ranging from visible to near infrared (400–1600?nm). depends on substrate doping, microstructuring fluence, annealing temperature. obtained room-temperature responsivities as high 100?A?W at 1064?nm, 2 orders magnitude higher than for standard photodiodes. For...

We fabricate submicrometer silicon spikes by irradiating a surface that is submerged in water with 400 nm, 100 fs laser pulses. These are less than micrometer tall and about 200 nm wide—one to two orders of magnitude smaller the microspikes formed irradiation gases or vacuum. Scanning electron micrographs show formation involves combination capillary waves on molten laser-induced etching silicon. Chemical analysis scanning microscopy they composed 20-nm-thick oxide layer.

We report on the formation of high-density regular arrays nanometer-scale rods using femtosecond laser irradiation a silicon surface immersed in water. The resulting exhibits both micrometer-scale and structures. structure consists spikes 5-10 mum width, which are entirely covered by that roughly 50 nm wide normal to spikes. involves several processes: refraction light highly excited silicon, interference scattered refracted light, rapid cooling water, roughness-enhanced optical absorptance,...

Intriguing anisotropic electrical and optoelectrical properties in two-dimensional (2D) materials are currently gaining increasing interest both for fundamental research emerging optoelectronic devices. Identifying promising new 2D with low-symmetry structures will be rewarding the development of polarization-integrated nanodevices. In this work, electron transport multilayer ternary Ta2NiSe5 were systematically researched. The polarization-sensitive photodetector shows a linearly anisotropy...

Abstract An extreme drought occurred in the Yangtze River Basin 2022, inflicting huge impacts nationwide. To provide a reference for prevention and mitigation, this paper presents comprehensive analysis of terms its characteristics, causes, impacts, response strategies. It concludes that stood out by long duration, wide impact range, severe intensity, as combined result abnormal high‐temperature weather massive social water consumption. Serious are observed various fields economy, including...

We report fabrication of regular arrays silicon microspikes by femtosecond laser irradiation a wafer covered with periodic mask. Without mask, form, but they are less ordered. believe that the mask imposes order diffracting beam and providing boundary conditions for capillary waves in laser-melted silicon.

We studied the pulse energy threshold of surface nano-/micro-morphology modifications by irradiating Si, GaAs, GaP, InP, Cu and Ti surfaces with 100 fs laser pulses at a wavelength 800 nm in air water. found that thresholds required for permanent modification water are up to 30% lower than those air. Different non-equilibrium dynamics processes melting layer cause different

Abstract 2D materials and their van der Waals heterostructures are of great fundamental interest have potential applications in emerging electronics devices. However, atomically thin photodetector suffered from performance limitations because low optical absorption. Here, a near‐infrared based on methylammonium lead halide perovskite quantum dots (MQDs), combined with Ta 2 NiSe 5 heterostructures, is fabricated to take advantage energy band alignment. An ultrasensitive photoresponse...

We study the morphology of borosilicate glass surface machined by femtosecond laser pulses. Our observations show that a thin rim is formed around ablated craters after single pulse. When multiple pulses are overlapped, crater rims also overlap and produce roughness. The appears to be resolidified splash from molten layer generated during ablation process. estimate this few micrometers thick exists for microseconds. During melt lifetime, forces acting on move it center edge crater.

The tertiary lymphoid structure (TLS) is recognized as a potential prognosis factor for breast cancer and strongly associated with response to immunotherapy. Inducing TLS neogenesis can enhance the immunogenicity of tumors improve efficacy However, our understanding region at single-cell level remains limited. Therefore, we employed high-resolution techniques, including RNA sequencing (scRNA-seq) spatial transcriptomics (ST), TLS-specific signature investigate regions in cancer. We...

Orthoexcitonic gas in cuprous oxide is generated by one and two photon resonant excitations at different excitation intensities temperatures between 1.8 4.2 K. The experimental results are analyzed simulation with a Boltzmann equation. When the exciton density low, observed luminescence found to originate from nonequilibrium excitonic where exciton-LA phonon scattering dominates. very high, not only but also exciton-exciton important. consists of systems: an system that distributed according...

A quantitative characterization of the wetting states droplets on hydrophobic textured surfaces requires direct measurement liquid penetration into surface cavities, which is challenging. Here, use quartz crystal microbalance (QCM) technology reported for depth a micropillar-patterned surface. The actual liquid–air interface droplet was established by freezing and characterizing it using cryogenically focused ion beam/scanning electron microscope (cryo FIB-SEM) technique. It found that...

Major interest in the analysis of mature plasma cell neoplasias mice and humans has focused on identification precursor cells that give rise to malignant cells. Although several laboratories have recently suggested such are present granulomas pristane-treated bone marrow some multiple myeloma patients, vivo cellular interactions required for their differentiation into tumors remains unclear. Given extensive peripheral T normal B cells, we assessed potential role plasma-cell tumor...

Excitation by two-photon resonant absorption may be able to maintain the temperature of orthoexcitonic system in ${\mathrm{Cu}}_{2}$O sufficiently low, resulting an excitonic density high enough allow us study quantum Bose-Einstein statistical properties a nearly ideal Bose gas. The luminescence spectra show that consists two parts. One follows usual statistics with chemical potential \ensuremath{\mu}=0. other is at energy position corresponding zero kinetic energy.

A ZnCdTe/ZnTe/ZnMgSeTe quantum-well (QW) structure lattice matched to ZnTe is proposed for the light-emitting devices in pure-green wavelength region. Thin layers are inserted between ZnCdTe QW layer and ZnMgSeTe cladding layers, which improve quality of as demonstrated by its narrow photoluminescence line width (6.5 meV at 10 K). Optically pumped lasing 552 nm room temperature with a threshold optical power 215 kW cm−2 achieved. The present results clearly show feasibility ZnTe-based...