Optical sensing in the mid- and long-wave infrared (MWIR, LWIR) is of paramount importance for a large spectrum applications including environmental monitoring, gas sensing, hazard detection, food product manufacturing inspection, so forth. Yet, such to date are served by costly complex epitaxially grown HgCdTe quantum-well quantum-dot photodetectors. The possibility exploiting low-energy intraband transitions make colloidal quantum dots (CQD) an attractive low-cost alternative expensive low...

Abstract The growing demand for efficient, compact, and cost‐effective short‐wave infrared (SWIR) emitters has surged due to their wide‐ranging applications in industries such as biomedical diagnostics, food pharmaceutical quality control, agriculture, environmental monitoring. Conventional SWIR sources are limited by bulkiness, inefficiency, high cost, while phosphor‐converted Light Emitting Diodes (pc‐LEDs) based on transition metal ions or lanthanides face challenges fixed wavelengths,...

Developing high performance, low-cost solid-state light emitters in the telecom wavelength bandwidth is of paramount importance for infrared light-based communications. Colloidal quantum dot (CQD) based emitting diodes (LEDs) have shown tremendous advances recent times through improvement synthesis chemistry, surface property, and device structures. Despite advancements CQD LEDs visible range with efficiency reaching theoretical limits, their short-wave (SWIR) counterparts mainly on lead...

Materials with optical gain in the infrared are of paramount importance for communications, medical diagnostics, and silicon photonics. The current technology is based either on costly III–V semiconductors that not monolithic to CMOS or Er-doped fiber does make use full transparency window. Colloidal quantum dots (CQDs) offer a unique opportunity as an medium view their tunable bandgap, solution processability, compatibility. 8-fold degeneracy CQDs Pb-chalcogenides has hindered demonstration...

The use of colloidal quantum dots (CQDs) as a gain medium in infrared laser devices has been underpinned by the need for high pumping intensities, very short lifetimes, and low coefficients. Here, PbS/PbSSe core/alloyed-shell CQDs are employed an that results highly suppressed Auger recombination with lifetime 485 ps, lowering amplified spontaneous emission (ASE) threshold down to 300 µJ cm-2 , showing record net modal coefficient 2180 cm-1 . By doping these engineered core/shell up nearly...

Steady-state access to intraband transitions in colloidal quantum dots (CQDs), via doping, permits exploitation of the electromagnetic spectrum at energies below band gap. CQD optoelectronics allows envisaging cheap mid- and long-wavelength infrared photodetectors light-emitting devices, which today employ epitaxial materials. As devices start emerge, thorough studies basic properties different materials are needed guide technological research. In this work, we investigate size temperature...

Solid-state broadband light emitters in the visible have revolutionized today's lighting technology achieving compact footprints, flexible form factors, long lifetimes, and high energy saving, although their counterparts infrared are still development phase. To date, relied on phosphor-downconverted based atomic optical transitions transition metal or rare earth elements phosphor layer resulting limited spectral bandwidths near-infrared preventing integration into electrically driven...

Pb-chalcogenide colloidal quantum dots (CQDs) are attractive materials to be used as tuneable laser media across the infrared spectrum. However, excessive nonradiative Auger recombination due presence of trap states outcompetes light amplification by rapidly annihilating exciton population, leading high gain thresholds. Here, a binary blend is employed CQDs and ZnO nanocrystals in order passivate in-gap PbS-CQD medium. Using transient absorption, fivefold increase measured lifetime...

Abstract Unbalanced charge injection is deleterious for the performance of colloidal quantum dot (CQD) light‐emitting diodes (LEDs) as it deteriorates efficiency, brightness, and operational lifetime. CQD LEDs emitting in infrared have previously achieved high efficiencies but only when driven to emit low‐radiance regime. At higher radiance levels, required practical applications, efficiency decreased dramatically view notorious droop. Here, a novel methodology reported regulate supply...

Abstract Broadband infrared photodetectors have profound importance in diverse applications including security, gas sensing, bioimaging, spectroscopy for food quality, and recycling, just to name a few. Yet, these can currently be served by expensive epitaxially grown photodetectors, limiting their market potential social impact. The use of colloidal quantum dots (CQDs) 2D materials hybrid layout is an attractive alternative design low‐cost complementary metal‐oxide‐semiconductor (CMOS)...

Abstract Colloidal semiconductor quantum dots (QDs) can be considered a promising material platform for solution‐processed laser diodes. However, due to some fundamental challenges, the realization of electrically pumped lasing based on QDs remains unresolved. Here, binary blend and ZnO nanocrystals is employed, which serve as nano‐sized scatterers facilitate waveguide gain in ultra‐thin films. By carefully engineering electric field these films, an infrared amplified spontaneous emission...

The optimization of a material functionality requires both the rational design and precise engineering its structural chemical parameters. In this work, we show how colloidal chemistry is an excellent synthetic choice for synthesis novel ternary nanostructured chalcogenides, containing exclusively noble metals, with tailored morphology composition potential application in energy conversion field. Specifically, Ag–Au–Se system has been explored from point view, which leads to set Ag2Se-based...

X-ray computed tomography (CT) is a powerful and widely used medical non-invasive technique that often requires intravenous administration of contrast agents (CAs) to better visualize soft tissues. In this work, we have developed novel CT agent based on ternary Ag–Au–Se chalcogenide nanoparticles (NP). A facile ligand exchange by using 3 kDa PEGylated with dithiol dihydrolipoic acid as an anchor group resulted in highly water-soluble monodisperse nanoparticles. These NPs were tested vivo...

The turn-on voltage of a light-emitting diode (LED) is an important parameter as it determines the power consumption LED and influences effective conversion efficiency. LEDs based on nanoscale engineering blended PbS [mixture quantum dots (QDs) with two different bandgaps] colloidal QDs have recently shown record performance in infrared region. One most intriguing findings for these devices substantially lower-than-bandgap achievement open circuit ( VOC), approaching radiative limit. In this...

Abstract Solution‐processed gain media have great technological potential as lasers due to their ease of integration with on‐chip photonics, scalability and tuneable optoelectronic properties. Currently, the spectral coverage solution‐processed extends from visible up telecom wavelengths in short‐wave infrared (SWIR) (<1650 nm). Here, optical extended SWIR 1600 nm 2500 is demonstrated, using PbSbased colloidal quantum dots (CQDs). This region has many applications such LIDAR, biological...

Cation exchange reactions have been exploited in the last years as an efficient tool for controlled chemical modification of premade nanocrystals. In this work, gradual transformation Ag2S nanocrystals into Au2S analogues is performed by sequential cation that allow a fine control composition, delivering also two intermediate ternary sulfides based exclusively on noble metals. The role different surfactants reaction medium has studied: while dodecylamine favoring heterogeneous nucleation...

Achieving low-threshold infrared stimulated emission in solution-processed quantum dots is critical to enable real-life applications including photonic integrated circuits (PICs), LIDAR application, and optical telecommunication. However, realization of low threshold gain fundamentally challenging due high degeneracy the first emissive state (e.g., 8-fold) fast Auger recombination. In this Letter, we demonstrate ultra-low-threshold with an onset 110 μJ cm–2 employing cascade charge transfer...

Metallic nanocrystals have been revealed in the past years as valuable materials for catalytic growth of semiconductor nanowires. Yet, only low melting point metals like Bi reported to successfully assist elongated CdX (X = S, Se, Te) systems solution, and possibility use plasmonic noble has become a challenging task. In this work we show that anisotropic CdSe nanostructures solution can also be efficiently catalyzed by colloidal Au nanoparticles, following preferential crystallographic...

The accurate engineering of interfaces between inorganic nanocrystals and semiconducting organic molecules is currently viewed as key for further developments in critical fields such photovoltaics photocatalysis. In this work, a new unconventional source interface interaction based on metal-metal bonds presented. With aim, an Au(I) organometallic gelator was exploited the formation hydrogel-like nanocomposites containing nanoparticles conjugated molecules. Noteworthy, establishment...

The work explores the reactions between Cu_2−xSe premade nanoparticles and a Pt(<sc>ii</sc>) precursor, confirms formation of ternary CuPtSe phases with flexible stoichiometry photocatalytic activity towards hydrogen evolution reaction.

The synergy between gelator molecules and nanostructured materials is currently a novel matter of study. possibility to carefully design the skeleton molecular entity as well nanostructure's morphological chemical features offers prepare huge variety nanocomposites with properties potentially different than just sum those individual building blocks. Here we describe synthesis characterization made by unconventional combination phosphine-Au(I)-alkynyl-based organometallic gelating plasmonic...

Achieving low-threshold infrared stimulated emission in solution-processed quantum dots is critical to enable real-life application including photonic integrated circuits (PICs), LIDAR and optical telecommunication. However, realization of low threshold gain fundamentally challenging due high degeneracy the first emissive state (e.g., 8-fold) fast Auger recombination. In this letter, we demonstrate ultralow-threshold with an onset 110 uJ.cm-2 employing cascade charge transfer (CT)...