Quantum dots attract significant attention as one of the most promising colloidal nanocrystals with unique optical properties and potential applications for the next generation of display technology. In this paper, we evaluate the performance of CdZnSeS-based alloyed-shell quantum dots (QDs) for electroluminescence devices upon additional shell growth and ligand exchange. This includes core/shell (C/S) and core/shell/shell (C/S/S) QDs, whose latter includes an additional ZnS shell and octanethiol (OT) ligands. We present detailed characterizations of QDs using transmission electron microscopy, XRD, and various spectroscopic techniques and demonstrate their QD light emitting (QLEDs). We find the photoluminescence quantum yield of C/S/S QDs increased from 68.8% to 88.7% compared to C/S QDs whereas the emission linewidth narrows from 22.2 nm to 20.8 nm. QLEDs fabricated with C/S/S QDs exhibit a higher peak external quantum efficiency (EQE) of 4.1% and maximum luminance of 85 000 cd m-2, compared to 2.3% EQE and 67 000 cd m-2for C/S QLEDs. In this respect, the OT-assisted shell growth significantly improves the optical property of QDs and performance of QLEDs, likely attributed to the enhanced charge balance and increased radiative recombination rate.

Green-emitting carbon dots (CDs) were synthesized via a solvent-free, vacuum-assisted method using citric acid and urea. The CDs exhibited strong photoluminescence and served as selective, sensitive probes for Cu 2+ detection in water, with a detection limit of 26 nM. Among the tested metal ions, Cu 2+ induced the most significant PL quenching. Time-resolved photoluminescence measurements of the CDs in the presence of Cu 2+ ions revealed a minimal change in lifetime, despite a significant decrease in PL intensity, along with unchanged UV–vis absorption, indicating a mixed quenching mechanism. The sensor’s applicability was confirmed in raisin extract and tea infusion, showing notable PL suppression. With their simplicity, selectivity, and sensitivity, these CDs offer promising potential as nanosensors for detecting Cu 2+ in environmental and real-world analytical settings.

Green-emitting carbon dots (CDs) were synthesized via a solvent-free, vacuum-assisted method using citric acid and urea. The CDs exhibited strong photoluminescence and served as selective, sensitive probes for Cu2+ detection in water, with a detection limit of 26 nM. Among the tested metal ions, Cu2+ induced the most significant PL quenching. Time-resolved photoluminescence measurements of the CDs in the presence of Cu2+ ions revealed a minimal change in lifetime, despite a significant decrease in PL intensity, along with unchanged UV-vis absorption, indicating a mixed quenching mechanism. The sensor's applicability was confirmed in raisin extract and tea infusion, showing notable PL suppression. With their simplicity, selectivity, and sensitivity, these CDs offer promising potential as nanosensors for detecting Cu2+ in environmental and real-world analytical settings.

In this work, we present a straightforward and cost-effective approach to synthesize multi-shell InP/ZnSe/ZnSeS/ZnS quantum dots (QDs) that show promising potential for use in photodetectors. By carefully layering ZnSe, ZnSeS, and ZnS shells around an InP core, we were able to enhance the stability and optical performance of the QDs, achieving a narrow emission peak of 45 nm and a high photoluminescence quantum yield of 55%. These QDs were then integrated into simple photodetector devices, which possessed impressive sensitivity and detection capabilities. Specifically, our devices achieved a peak responsivity of 0.54 A W ^−1 and a detectivity of 2.22 × 10 ^11 Jones at 400 nm with a 5 V bias. This study highlights the potential of InP-based QDs as a safer and more sustainable alternative to traditional QDs that contain toxic heavy metals, offering a viable path forward for developing high-performance optoelectronic devices. Our findings suggest that these InP/ZnSe/ZnSeS/ZnS QDs could be a key material for the next generation of high-performance optoelectronic devices, especially in applications that require highly sensitive and stable photodetectors.

This study reports the design and synthesis of high-performance PEGylated CdSe/ZnS@Fe₂O₃ yolk-shell nanoparticles (NPs) for the efficient photocatalytic degradation of Methylene Blue (MB), a dye-stuff with toxic effects in water. The novelty of this work lies in the synergistic integration of a narrow-bandgap CdSe core and a ZnS shell with a Fe₂O₃ layer, further stabilized by a precise PEGylation process to ensure superior colloidal stability and surface activity in aqueous media. The morphological and structural properties of the synthesized nanostructures were investigated through TEM and XRD analyses, and their crystal structure and phase formation were successfully determined. FTIR and EDX analyses validated the successful surface functionalization and elemental composition. Particle size and zeta potential measurements revealed that an optimal 20% PEG concentration prevents agglomeration and maintains a high photoluminescence quantum yield of 62%. Photocatalytic tests demonstrated that the PEG:(CdSe/ZnS@Fe₂O₃) system achieves an outstanding degradation rate constant of 63.12*10-3 min-1 under UV light, reaching 84.2% efficiency within only 30 minutes. These results highlight the potential of these yolk-shell NPs as a robust and efficient catalyst for rapid wastewater treatment.

This study delves into the transformative effects of inorganic gold chloride (AuCl) doping on all-inorganic cesium lead bromide (CsPbBr3) colloidal perovskite quantum dots (PeQDs). Using a precise hot injection synthesis method, AuCl was introduced at concentrations ranging from 0 to 10

In this work, we report a simple and cost-effective method for improving both the environmental stability and photoluminescence quantum efficiency (PLQY) of perovskite nanocrystals (PNCs). Through their embedding in a specially designed macroporous polydimethylsiloxane (MPDMS) matrix and incorporation of plasmonic gold nanoparticles (Au NPs), remarkable improvements are achieved. The resulting MPDMS@PNC composites are seen to retain near-unity quantum efficiency even after 24-h immersion in water and are observed to retain over 85

Colloidal quantum wells, also known as colloidal nanoplatelets (NPLs), have emerged as a promising class of materials for light‐emitting devices (LEDs). However, the most widely studied core/shell NPLs, which rely on cadmium‐based shell layers, face challenges due to toxicity concerns and improper charge confinement. To address these limitations, a new synthetic approach is presented that enables the controlled growth of zinc chalcogenide‐based shell layers on NPLs. The synthesized CdSe/ZnSe core/shell NPLs exhibit emission between 615 and 630 nm, with a moderate photoluminescence quantum yield (PL‐QY) of 40–50%. It is also demonstrated that the lateral dimensions of the CdSe core NPLs significantly affect the optical properties of the core/shell heterostructures, with smaller lateral dimensions resulting in narrower emission linewidths as low as 20 nm. Further passivation of these core/shell NPLs with an additional ZnS shell layer significantly increases the PL‐QY up to 80–90%. Finally, the device performance of these two core/shell NPLs is investigated by fabricating solution‐processed LEDs. With LEDs incorporating CdSe/ZnSe/ZnS core/multi‐shell NPLs as the active light‐emitting layer, an external quantum efficiency (EQE) of 3.82% and a maximum brightness of 6477 cd m − 2 is obtained. These findings underscore the significant potential of zinc chalcogenide‐based shell layers in advancing colloidal NPLs toward high‐performance light‐emitting devices.

Graphene quantum dots (GQDs) with bright emission at short wavelengths have attracted much attention due to their importance in various applications such as light-emitting diodes. During or after synthesis, several parameters can significantly improve the optical properties of GQDs. This study presents a facile solvothermal method with low-cost precursors using glutamic acid as the carbon source to realize blue emitting GQDs. The positive effects of urea and 1-octanethiol as nitrogen and sulfur dopants on the photoluminescence quantum yield (PLQY) of the prepared GQDs were demonstrated and optimized. The results confirmed the formation of 2.2 nm nanoparticles with a bright emission around 381 nm with a full width at half maximum of 58 nm and a PLQY approaching 70%. The decay lifetime of the emission also showed a tri-exponential profile with an average lifetime of 2.4 ns. The simplicity of the preparation method without any post-treatment process, together with a high PLQY of 70% at short wavelengths, nominates the prepared GQDs for optoelectronics and UV light-driven biological purposes.

Perovskite nanocrystals (PeNCs) are emerging as exceptional materials due to their high photoluminescence quantum yield, tunable bandgap, and excellent charge carrier mobility, enabling a wide range of colors and promising applications in optoelectronics and photovoltaics. Despite their advantages, PeNCs face stability challenges caused by environmental factors. In the presented study, a facile and versatile colloidal hot-injection method was used to apply the beneficial aspects of Zn-doping in cesium lead bromide (CsPbBr3) PeNCs. The uniform platelet-shaped Zn-doped CsPbBr3 PeNCs were prepared by doping with a 0.1 molar ratio of zinc-oleate solution in the perovskite precursors during synthesis. Then, zinc-oxide (ZnO) and nickel-oxide (NiO) coating layers were utilized separately to effectively reduce surface defects, encapsulate PeNCs, and improve their stability issues. To fabricate the coated PeNCs with metal oxides, zinc acetate and nickel(II) acetate tetrahydrate solutions were prepared individually and added to the crude perovskite solutions. The quantum yield of Zn-doped CsPbBr3 (CsPb1-xZnxBr3) PeNCs coated with ZnO increased from 50% for bare CsPbBr3 to over 84%, while NiO-coated PeNCs exhibited a higher yield of 90% both of which remarkably enhanced the emission stability. Moreover, NiO coatings represented a proper protection against surface imperfections and improved resistance to external stimuli. The combination of facile/effective preparation method, excellent emission efficiency, and reliable emission stability nominates the prepared colloidal composite for display pixels, detectors, and lasers.

Forgery, a serious universal problem, is causing huge economic losses every year. Against forgery, information‐encoded labelling systems have attracted significant attention for a diverse range of anti‐counterfeiting applications. Here, cost‐effective and ultra‐durable nanocrystal‐based labels are proposed and demonstrated in which information can be encoded as physically unclonable functions (PUFs) of hardware‐oriented security systems. The fabrication method of the PUFs is based on the self‐assembly of colloidal quantum wells (CQWs) and generation of unclonable features within their pattern at a liquid–liquid interface. These CQW PUFs are analyzed with well‐known statistical tests, which show a uniqueness level of 0.5060 ± 0.0323 and prove their randomness. In addition, a feature‐matching algorithm is used to authenticate these information‐encoded CQW PUFs. For the safety of the semiconductor chips, a CQW PUF is attached to the surface of the chip to protect against hardware cyber‐attacks. Eventually, fabricated labels are examined against high temperatures and moisture environments. The fabricated CQW label is durable for a period of 150 days it is tested, demonstrating ultra‐high stability of the label. High stability and durability, cost‐effectiveness, and high encoding capacity make these proposed nanocrystal labels extremely attractive for large‐scale commercialization.

The presented study introduces optimized blue-emissive carbon dots (CDs) with high photoluminescence efficiency up to 65 % at 416 nm, large Stokes shift (69 nm), and full-width at half maximum (FWHM) of 73 nm. Xray photoelectron spectroscopy confirmed the formation of carbon-based bonds as the main component of CDs, with reliable amounts of O, S, and N as dopant components. These features, along with single-exponential time-decay profile at long average lifetime of 10.05 ns, supported the significant role of uniformly distributed mid-gap energy levels in the recombination process. The simplicity, low-cost, non-toxicity, and short reaction time of CDs, along with their excellent emission properties in the deep-blue region, make them suitable for use in environmental monitoring and high-contrast bioimaging.

Luminescent carbon dots (CDs) possess a range of fundamental and technological advantages, including low-cost, and scalable preparation methods, high emission efficiency, tunable electronic properties, and adaptable surface characteristics. However, aggregation-caused quench in solid-state emission of CDs has constrained their applications in luminescent solar-concentrators, and light-emitting devices. This study introduces a rapid and straightforward microwave method for producing bright blue-and green-emissive CDs, with emission peaks at 440 nm and 520 nm, respectively. Blue-CDs showed excitation-dependent feature with a biexponential decay profile and average lifetime of 6.3 ns, while the green one signified an excitation-independent photoluminescence profile with longer average lifetime of 9 ns through biexponential fitting of decay plot. Upon optimization of experimental parameters, reproducible green emission with a high efficiency of 78 % was achieved in dimethyl sulfoxide (DMSO). The critical role of biurea as a nitrogen precursor was elucidated through experimental and computational investigations. Furthermore, owing to the bright solid-state emission of the synthesized CDs, they were utilized as color-converting layers in the fabrication of durable monochrome LEDs, yielding blue and yellowish-green emissions with Commission Internationale de L'Eclairage (CIE) coordinates of (0.16, 0.10) and (0.35, 0.57), respectively. This study highlights the potential of CDs for applications in light-emitting panels.

Electroluminescent white light-emitting diodes (WLEDs) are always of great interest for emerging display applications. Carbon-based quantum dots (CQDs) are the newest emerging nanoscale materials that can be employed for this purpose, owing to their broad and bright light emission properties. In the present work, highly luminescent CQDs with an emission quantum yield of 60% were prepared via a colloidal solvothermal method and subsequent silica gel column chromatography. The photoluminescence (PL) peak was located at 550 nm possessing yellow emission, with a full width at half-maximum of 98 nm and a relatively long lifetime of 10.23 ns through a single-exponential recombination pathway. CQDs were employed in an electroluminescent device architecture of an ITO/PEDOT:PSS/TFB/CQD:PVK/TPBi/LiF/Al structure and blended with poly(N-vinylcarbazole) (PVK) to evaluate their ability to reach white electroluminescent emission. Results confirmed a high external quantum efficiency (EQE) of 0.76% and a maximum luminescence of 774.3 cdm(-2). Tuning the ratio between CQDs and PVK from 1:10.25 to 1:5.75 resulted in a systematic shift in CIE x-y coordinates from 0.23-0.26 to 0.21-0.24, located close to the cool white region. The results of the present study can be considered a step forward in fabricating efficient WLEDs based on low-cost CQDs.

The aerospace industry has progressively grown its use of composites. Electrically conductive nanocomposites are among important modern materials for this sector. We report on a bulk composite containing silver nanowires (AgNW) and an aerospace grade epoxy for use in carbon fiber reinforced polymers (CFRPs). AgNWs’ surfaces were also modified to enhance their ability to be dispersed in epoxy. Composites were obtained by use of three-roll milling which is of major interest for industrial applications, especially for the aerospace sector, since the process is scalable and works for aerospace grade resins with high curing temperatures. Our main objective is to improve the electromagnetic interference (EMI) shielding performance of CFRPs via improving the properties of the resin material. The addition of AgNWs did not considerably alter the flexural strength of the epoxy, however the composite with surface-modified AgNWs has a 46 % higher flexural strength. Adding AgNWs over a low threshold concentration of 0.05 wt% significantly enhanced the electrical conductivity. Conductivities above the percolation threshold lie around 102 S/m. At a concentration of 5 wt% AgNW, the EMI shielding efficiency (SE) of epoxy increased from 3.49 to 12.31 dB. Moreover, the thermal stability of the epoxy was unaffected by AgNWs. As a result, it was discovered that (surface modified) AgNWs improved the (multifunctional) capabilities of the aerospace grade epoxy resin which might be used in CFRPs to further enhance properties of composites parts, demonstrating suitability of AgNWs’ as a reinforcement material in aerospace applications.

Perovskite nanocrystals (PNCs) have found extensive utility across diverse technological applications in optoelectronics; nevertheless, their susceptibility to environmental instability poses a significant constraint on their practicality. Within this investigation, we present a novel and facile approach for the development of highly stable superhydrophobic PNCs. These engineered superhydrophobic perovskite nanocrystal composites, referred to as HSNPs@PNCs, demonstrate remarkable optoelectronic attributes, provided that their inherent instability can be effectively mitigated. HSNPs@PNCs manifest an impressive water contact angle of 172 degrees and an exceedingly low sliding angle of 1 degrees, thus showcasing their exceptional superhydrophobicity. Of particular note is the extraordinary stability exhibited by HSNPs@PNCs despite aqueous environments, thermal fluctuations, and UV exposure. Remarkably, even after a prolonged 30 -day immersion in water, this nanocomposite maintains an outstanding emission efficiency of 75 %. Furthermore, the method of application through a spray deposition technique circumvents sample size limitations, thereby amplifying their suitability for industrial applications. Moreover, this study extends the practicality of HSNPs@PNCs by enabling their homogeneous coating onto various surfaces such as glass, fabric, and aluminum, yielding luminescent superhydrophobic surfaces. This approach liberates the substrates from constraints, significantly broadening the potential spectrum of applications for these materials within diverse industrial and technological domains.

Quantum dot light-emitting diodes (QLEDs) hold great promise for next-generation display applications owing to their exceptional optical properties and versatile tunability. In this study, we investigate the effects of quantum dot (QD) shell thickness, polyethylenimine (PEI) concentration, and PEI layer position on the performance of inverted QLED devices. Two types of alloyed-core/shell QDs with varying shell thicknesses were synthesized using a one-pot method with mean particle sizes of 8.0 ± 0.9 nm and 10.3 ± 1.3 nm for thin- and thick-shelled QDs, respectively. Thick-shelled QDs exhibited a higher photoluminescence quantum yield (PLQY) and a narrower emission linewidth compared to their thin-shelled counterparts. Next, QLEDs employing these QDs were fabricated. The incorporation of PEI layers on either side of the QD emissive layer significantly enhanced device performance. Using PEI on the hole transport side resulted in greater improvement than on the electron injection side. Sandwiching the QD layer between two PEI layers led to the best performance, with a maximum external quantum efficiency (EQE) of 17% and a peak luminance of 91,174 cd/m2 achieved using an optimized PEI concentration of 0.025 wt% on both electron injection and hole injection sides. This study highlights the critical role of QD shell engineering and interfacial modification in achieving high-performance QLEDs for display applications.