Size Of Quantum Dots Research Articles

CoP Quantum Dots Embedded in Carbon Polyhedra through Co─P─C Bonding Enabling High‐Energy Lithium‐Ion Capacitors

AbstractPhosphides with high theoretical capacity are considered ideal anode materials for lithium‐ion capacitors (LICs), but poor electronic conductivity as well as unsatisfied cyclic stability limits the performance of the phosphides. Here a covalently bonded CoP@C heterostructure is reported, which consists of 5 nm CoP quantum dots (QDs) like pomegranate seeds pinned in carbon polyhedron through interfacial Co─P─C bonding. The ultrafine size of CoP QDs provides more reactive sites and a shorten electrons/ions diffusion path, boosting the specific capacity. The Co─P─C bond induces the energy band variation of CoP and increases the interfacial charge density, bringing about fast kinetics. Besides, the Co─P─C bond introduces a robust pining effect among CoP QDs and carbon polyhedra, greatly improving the structure stability of 5 nm CoP QDs. The CoP@C heterostructure electrode exhibits high capacity (nearly 1000 mAh g−1) and superior cycling stability. It is worth noting that a prototyped LIC full‐cell of YP80//CoP@C presents an impressive high energy density of 172 Wh kg−1 and a power density of 10.8 kW kg−1. Moreover, the LIC possesses an ultra‐long life, retaining 80% after 20,000 cycles. This study offers an effective design for phosphides achieving fast kinetics and superior structure stability through an interfacial bonding approach.

Theoretical Analysis of GeSn Quantum Dots for Photodetection Applications.

GeSn alloys have recently emerged as complementary metal-oxide-semiconductor (CMOS)-compatible materials for optoelectronic applications. Although various photonic devices based on GeSn thin films have been developed, low-dimensional GeSn quantum structures with improved efficiencies hold great promise for optoelectronic applications. This study theoretically analyses Ge-capped GeSn pyramid quantum dots (QDs) on Ge substrates to explore their potential for such applications. Theoretical models are presented to calculate the effects of the Sn content and the sizes of the GeSn QDs on the strain distributions caused by lattice mismatch, the band structures, transition energies, wavefunctions of confined electrons and holes, and transition probabilities. The bandgap energies of the GeSn QDs decrease with the increasing Sn content, leading to higher band offsets and improved carrier confinement, in addition to electron-hole wavefunction overlap. The GeSn QDs on the Ge substrate provide crucial type-I alignment, but with a limited band offset, thereby decreasing carrier confinement. However, the GeSn QDs on the Ge substrate show a direct bandgap at higher Sn compositions and exhibit a ground-state transition energy of ~0.8 eV, rendering this system suitable for applications in the telecommunication window (1550 nm). These results provide important insights into the practical feasibility of GeSn QD systems for optoelectronic applications.

PbS Quantum Dots Ink with Months-Long Shelf-Lifetime Enabling Scalable and Efficient Short-Wavelength Infrared Photodetectors.

The phase-transfer ligand exchange of PbS quantum dots (QDs) has substantially simplified device fabrication giving hope for future industrial exploitation. However, this technique when applied to QDs of large size (>4nm) gives rise to inks with poor colloidal stability, thus hindering the development of QDs photodetectors in short-wavelength infrared range. Here, it is demonstrated that methylammonium lead iodide ligands can provide sufficient passivation of PbS QDs of size up to 6.7nm, enabling inks with a minimum of ten-week shelf-life time, as proven by optical absorption and solution-small angle X-ray scattering. Furthermore, the maximum linear electron mobility of 4.7×10-2cm2V-1s-1 is measured in field-effect transistors fabricated with fresh inks, while transistors fabricated with the same solution after ten-week storage retain 74% of the average starting electron mobility, demonstrating the outstanding quality both of the fresh and aged inks. Finally, photodetectors fabricated via blade-coating exhibit 76% external quantum efficiency at 1300nm and 1.8×1012Jones specific detectivity, values comparable with devices fabricated using ink with lower stability and wasteful methods such as spin-coating.

Gamma Ray-Induced Changes in Polyvinyl Alcohol/Carboxymethyl Cellulose/Cadmium Selenide Nanocomposite Films: Optical Analysis for Optoelectronic Devices

In order to create nanocomposite films (NC) of polyvinyl alcohol, carboxymethyl cellulose and cadmium selenide nanoparticles (PVA/CMC/CdSe), thermolysis and ex-situ casting techniques were used. The microstructure and shape of the CdSe nanoparticles (NP) were characterized with the Rietveld method and transmission electron microscopy (TEM). Rietveld refinement of the x-ray data showed that the prepared CdSe NP had the cubic zinc blend structure with a lattice parameter 6.057 Å. The TEM showed the formation of the dotted shape of CdSe with a particle size around 2 nm, confirming the quantum dot size of the mother phase CdSe. Samples from the prepared PVA/CMC/CdSe films were irradiated with γ radiation doses of 20−150 kGy. The resultant effects of the γ ray irradiation on the optical and color properties of the prepared films were investigated using UV–vis spectroscopy and the International Commission on Illumination (CIE) color difference technique. When the γ dose was increased to 150 kGy, the maximum dose used, the direct and indirect optical band gaps (Eg) decreased. We attribute this decrease to the domination of crosslinking that destroyed the ordered structure and thus increased the amorphous regions. In addition, we used the optical dielectric loss (ε”) to identify the type of microelectronic transition for the PVA/CMC/CdSe NC samples, which was found to be a direct allowed transition. The effect of γ ray irradiation on the absorbance, extinction coefficient, refractive index, dielectric parameters and optical conductivity of the NC samples were studied. The enhancement in the optical properties indicated that the γ radiation is a useful tool that allows the use of the resulting PVA/CMC/CdSe NC in optoelectronic devices. Finally, the color differences between the pristine and irradiated films were estimated. The irradiated PVA/CMC/CdSe NC film exhibited significant color differences relative to the pristine films.

Proton-Prompted Ligand Exchange to Achieve High-Efficiency CsPbI3 Quantum Dot Light-Emitting Diodes

HighlightsA new proton-promoted in situ ligand exchange strategy based on CsPbI3 quantum dots.The ligand exchange strategy maintains the quantum confinement effect of quantum dots and significantly improves the stability and photophysical properties of CsPbI3 quantum dots.The performance of light-emitting diodes based on CsPbI3 quantum dots is significantly improved, the external quantum efficiency is increased from 18.63% to 24.45%, and the half-operational lifetime is increased by 70 times.

Quantifying the Size‐Dependent Exciton‐Phonon Coupling Strength in Single Lead‐Halide Perovskite Quantum Dots

AbstractOptimizing the performance of semiconductors in both classical and quantum applications, not only requires a solid understanding of elementary excitations such as electrons, holes, or bound electron–hole pairs (excitons), but also of their interaction with the host material's vibrational states (phonons). Exciton‐phonon coupling is particularly relevant in quantum dots (QDs) of APbX3 lead‐halide perovskite (where “A” can be Cs, formamidinium (FA), or methylammonium (MA), and X can be Cl, Br, or I), a new class of semiconductors with a soft crystal structure. Here, they quantify the strength of coupling to interband transitions for both FAPbBr3 and CsPbBr3 QDs, via the magnitude of phonon replicas in their photoluminescence (PL) spectra at cryogenic temperatures. CsPbBr3 QDs exhibit weaker exciton‐phonon coupling than similarly sized FAPbBr3 QDs. While the phonon energies are size‐independent, the exciton‐phonon coupling strength decreases with increasing QD size due to the decreased coupling of the transition to low‐energy surface‐enhanced phonon modes, consistent withab initio molecular‐dynamics (AIMD) simulations. Furthermore, within the harmonic approximation, the size‐dependent PL linewidth at room temperature can coarsely be estimated from the low‐temperature phonon replica spectrum, highlighting the crucial role of anharmonic effects. These findings contribute to realizing perovskite QD‐based devices with narrow and coherent emission for quantum technologies.

A Facile Approach to Develop Polyvinyl Alcohol‐Based Bio‐Triboelectric Nanogenerator Containing Graphene‐ Doped Zinc Oxide Quantum Dots

This article presents an environmentally friendly, low‐cost polymer nanocomposite, polyvinyl alcohol/sodium alginate‐graphene‐zinc oxide (PVA‐SA/G‐ZnO) based triboelectric nanogenerator by spin coating. ZnO quantum dots of average particle size <10 nm and the graphene oxide (GO)‐doped ZnO are synthesized by co‐precipitation following ageing. ZnO and G‐ZnO particles are filled into the PVA/SA blend system using the solution mixing method. Spin‐coated films of ≈1.2 μm and casted films of 120 μm thicknesses were used to prepare triboelectric nanogenerators (TENGs) to test the output voltage performances. Irrespective of the thickness values, the films gave similar voltage responses with contact electrification. This illustrates triboelectric power generation as a surface charge carrier phenomenon based on morphological analyses by scanning electron microscope (SEM) and atomic force microscopy (AFM). The maximum output voltage of 0.24 V was approximately 5 times higher for the PVA/SA composite containing 2 wt% G‐ZnO nanomaterials compared to the neat polymer are obtained. The nanocomposites also demonstrate excellent dielectric constant (22 times higher) values, suggesting the role of the biodegradable thin‐film TENGs in various self‐powering devices.

Realizing High Performance Tunable Sensing Mode and Selectivity of Metal Ions Based on Carbon Dot

AbstractWe have adopted a straightforward, eco‐friendly and economically profitable pyrolysis route of tailoring quantum dot size carbon particles (CD) from the leaves of Arundo donax. The synthesized uniformly dispersed CD1 and CD2 have an average diameter of 4.5 nm and 3.5 nm respectively as determined via HRTEM. FT‐IR analysis corroborated nitric acid treatment leads to rich surface functionalization of CD2. Experimentally estimated average fluorescence (FL) lifetime of the as‐prepared CD1 and CD2 are 2.31 ns and 3.87 ns respectively. Juxtapose to other metal ions, Cd+2 ions can efficiently quench FL of CD1, while Cr+6 ions, on contrary, prominently enhanced FL of CD2. Benefitting from their FL response, a turn off sensor was built using CD1 to detect Cd+2 ions and a turn on‐off sensor by CD2 to sense Cr+6 with impressive limit of detections of 2.58 nM and 1.73 nM respectively. They exhibit superior performance compare to other documented nanoscopic materials. The FL “turn off” interaction mechanism of CD1 was attributed mainly to static quenching. While that of “turn on‐off” mechanism for CD2 was ascribed to chelation enhanced fluorescence phenomenon and a rare partial combination of inner filter effect plus dominate dynamic type of quenching.

Spatial-Arrangement-Assisted Emission Energy Fine Tuning of CdSe Quantum Dots (QDs) in QD–Block Copolymer Complexes

Quantum dots (QDs) exhibit size-dependent optical properties, where both the absorption and fluorescence energy levels vary with QD size. However, this dependence results in a discontinuity of intrinsically accessible energy levels for the bandgap, posing challenges in achieving precise energy tuning within a specific range. Herein, we demonstrate emission energy control of QDs with identical absorption energy levels by manipulating the spatial arrangement of QDs within QD–polymer complexes through hydrophobic interactions. The phase behavior of the QD–polymer complexes was modulated by adjusting the mass fraction of hydrophilic and hydrophobic blocks in the block copolymer, utilizing two types of amphiphilic block copolymers and varying temperatures. The QDs were spontaneously trapped within the hydrophobic region of the polymer template in water, resulting in spherical, cylindrical, and vesicle structures of QD–polymer complexes, corresponding to spherical, cylindrical, and layered assemblies of QDs, respectively. Depending on the QDs’ location within the QD–polymer complex, the surface area in contact with water varied, leading to different degrees of oxidation and, consequently, a change in the fluorescence energy level of QDs. This study introduces a novel method to fine tune the emission energy (<15 eV) of QDs by adjusting the polymer form factor without complicated procedures.

Effects of anisotropy on the electronic structure and nonlinear optical rectification in a quantum dot with hydrogen molecular ion

In this study, the effects of anisotropy and quantum dot size on energy levels and nonlinear optical rectification of a D_{2}^{ + } molecular complex confined to a two-dimensional quantum dot are investigated. The energy eigenvalues and corresponding eigenfunctions of the resulting eigenvalue equation are obtained using the adiabatic approach and the two-dimensional diagonalization method. We conclude that the evolution of the energy spectrum depends predominantly on the anisotropy-induced change of geometric confinement size. In addition, it has been determined that the peak position of the nonlinear optical rectification shifts to lower or higher energies as the asymmetry of the system increases, depending on whether the QD is in the oblate or prolate case. This feature can be considered an advantage in tuning the nonlinear optical properties of systems based on two-dimensional semiconductor heterostructures.

Study on the photovoltaic characteristics of solar cells based on PbS quantum dots and carbon counter electrode

Lead sulfide (PbS) quantum dots (QDs) with their customizable and precise energy levels, have emerged as highly promising photosensitizers in quantum dots sensitized solar cells (QDSSCs). This research focuses on fabricating high-performance QDSSCs anchored on PbS QDs sensitized mesoporous titania coated FTO electrodes. The PbS QDs were grown on mesoporous TiO2 through the Successive Ionic Layer Absorption and Reaction (SILAR) method. The optical properties were analyzed using UV–visible absorption spectroscopy, revealing that the SILAR cycles impacted the size and band gap of the PbS QDs. By analyzing the absorption data and the hyperbolic band model (HBM), the size of the PbS QDs were estimated to be 1.65 nm, 2.126 nm, 2.326 nm, 2.5692 nm, and 3.048 nm for 1 to 5 SILAR cycles, respectively. The effect of SILAR cycles was investigated, demonstrating a direct correlation between the number of SILAR cycles and the photovoltaic performance of the device. The maximum power conversion efficiency of 2.07 % was attained using 2 SILAR cycles, in contrast to 1.33 % and 1.63 % obtained with one and three SILAR cycles, respectively. Furthermore, impedance spectroscopy (IS), (Cs-V) (Rs-V) was employed at different frequencies, highlighting lowest series resistance for 2 SILAR cycles confirming its highest photovoltaic performance. Moreover, The utilization of a low-cost polysulfide electrolyte and carbon electrode has yielded superior or comparable outcomes compared to previously reported data.

CuS-NPs, GQD, MSN-NPs and doxorubicin: An excellent nano-compound for cancer treatment by chemo-photodynamic therapy

This study aims to create a nanocomposite that combines copper sulfide nanoparticles as a photosensitizer, graphene quantum dots as drug absorbers, mesoporous silica nanoparticles as a delivery mechanism, and doxorubicin, a traditional chemo dynamic drug used in cancer therapy. This novel nanocomposite aims to simultaneously utilize both photodynamic therapy and chemotherapy methods for cancer treatment. An 808 nm LED laser with 1 W power was used as a photodynamic therapy radiation source. Various techniques such as the transmission electron microscope, X-ray diffraction, Brunauer–Emmett–Teller/Barrett–Joyner–Halenda analysis, infrared Fourier spectroscopy, and UV–visible analysis were employed to determine the structural characteristics and optical properties of the synthesized nonocomposite. The sizes of graphene quantum dots, copper sulfide nanoparticles, and mesoporous silica nanoparticles were found to be approximately 40 nm, 8 nm, and 50 nm, respectively. The porosity analysis and specific surface area revealed that the optimized mesoporous silica nanoparticles have a high specific surface area of 717.76 m2 g−1, an appropriate pore size of 4.44 nm, and a well-defined pore volume of 0.99 cm3 g−1. These characteristics make them an up-and-coming agent for the delivery of anticancer drugs. The nanocomposite demonstrated a drug-loading capacity of 89%. Our findings showed a significant decrease in the absorption of anthracene composite after 10 min of laser irradiation, indicating the generation of reactive oxygen species.

Ultrabright fluorescent particles via physical encapsulation of fluorescent dyes in mesoporous silica: a mini-review.

Harnessing the power of mesoporous silica to encapsulate organic fluorescent dyes has led to the creation of an extraordinary class of nanocomposite photonic materials. These materials stand out for their ability to produce the brightest fluorescent particles known today, surpassing even the luminosity of quantum dots of similar spectrum and size. The synthesis of these materials offers precise control over the shape and size of the particles, ranging from the nano to the multi-micron scale. Just physical encapsulation of the dyes opens new possibilities for mixing different dyes within individual particles, paving the way for nearly limitless multiplexing capabilities. Moreover, this approach lays the groundwork for the development of highly sensitive sensors capable of detecting subtle changes in temperature and acidity at the nanoscale, among other parameters. This mini-review highlights the mechanism of synthesis, explains the nature of ultrabrightness, and describes the recent advancements and future prospects in the field of ultrabright fluorescent mesoporous silica particles, showcasing their potential for various applications.

Multifunctional tunable Cu2O and CuInS2 quantum dots on TiO2 nanotubes for efficient chemical oxidation of cholesterol and ibuprofen.

In this study, a CuInS2/Cu2O/TiO2 nanotube (TNT) heterojunction-based hybrid material is reported for the selective detection of cholesterol and ibuprofen. Anodic TNTs were co-decorated with Cu2O and CuInS2 quantum dots (QDs) using a modified chemical bath deposition (CBD) method. QDs help trigger the chemical oxidation of cholesterol by cathodically generating hydroxyl radicals (˙OH). The small size of QDs can be used to tune the energy levels of electrode materials to the effective redox potential of redox species, resulting in highly improved sensing characteristics. Under optimal conditions, CuInS2/Cu2O/TNTs show the highest sensitivity (∼12 530 μA mM-1 cm-2, i.e. up to 11-fold increase compared to pristine TNTs) for cholesterol detection with a low detection limit (0.013 μM) and a fast response time (1.3 s). The proposed biosensor was successfully employed for the detection of cholesterol in real blood samples. In addition, fast (4 s) and reliable detection of ibuprofen (with a sensitivity of ∼1293 μA mM-1 cm-2) as a water contaminant was achieved using CuInS2/Cu2O/TNTs. The long-term stability and favourable reproducibility of CuInS2/Cu2O/TNTs illustrate a unique concept for the rational design of a stable and high-performance multi-purpose electrochemical sensor.

Reactivity-matched synthesis of monodisperse Ag(In,Ga)S2 QDs with efficient luminescence.

I-III-VI quantum dots (QDs) have gained widespread attention owing to their significant advantages of non-toxicity, large structural tolerance, and efficient photoluminescence potential. However, the disbalance of reactivity between the elements will result in undesired products and compromised optical properties. Reducing the activity of highly reactive group IB elements is the most common approach, but it will reduce the overall reactivity and lead to a wide dispersion of QD sizes. In this study, we propose a method to improve the overall reactivity of the reaction system using the highly active IIIA precursor InI3, which triggers rapid nucleation and promotes the formation of Ag(In,Ga)S2 (AIGS) QDs, resulting in monodisperse particle size distributions and a significantly improved photoluminescence quantum yield (PLQY) (from 12% to 72%). Furthermore, narrow band edge emission is realized by coating a gallium sulfide (GaSx) shell on the basis of obtaining high-quality AIGS QDs. The core/shell QDs exhibit a 90% PLQY with a full width at half maximum (FWHM) of only 31 nm at 530 nm. This study provides a viable design strategy to synthesize monodisperse AIGS QDs with a narrow peak width and efficient luminescence, promoting the application of AIGS QDs in the field of luminescent displays.

Effect of cubic and spherical quantum dot size and size dispersion on the performance of quantum dot solar cells

We investigated the effect of cubic and spherical quantum dot size and size dispersion (size non-uniformity) on the absorption coefficient of a quantum dot ensemble. The absorption spectra of the cubic and spherical quantum dots (QDs) ensemble are found to be strongly dependent on the average size of QDs and the size distribution of QDs. Furthermore, we studied the effect of cubic and spherical quantum dot size and size dispersion on the QD photocurrent and efficiency of quantum dot solar cells (QDSCs). It is observed that there is an optimum size and size dispersion of QDs to achieve maximum QD photocurrent and efficiency. Embedding InAs QDs into the intrinsic region of a GaAs n-i-p solar cell improves performance from 20.3% to an ideal maximum of 34.4% (QDSC with cubic QD ensembles) and 36.5% (QDSC with spherical QD ensembles). The result shows that spherical morphology is better than cubic morphology. This theoretical study demonstrates that to achieve the highest possible power conversion efficiency, a suitable QD shape, optimized QD size, and size dispersion must be selected.

Integrated Biotic–Abiotic Solar Driven NADPH Regeneration Platform in Escherichia coli for Chemical Biomanufacturing Applications

AbstractThe development of a biohybrid bacterium capable of self‐synthesizing photocatalytically active quantum dots (QDs) is reported using the expression of a template protein that dictates the QDs size and properties. This biotic–abiotic light‐harvesting module is utilized for solar‐driven NADPH regeneration within the living bacteria, facilitated by controlled expression of ferredoxin NADP+ reductase. It is shown that the co‐expression of the latter is crucial for the selective production of biologically active 1,4‐NADPH. Upon irradiation, an 8.5‐fold increase in intracellular NADPH/NADP+ levels is shown, creating a pool of reducing equivalents available for reductive biocatalysis. This module is then utilized for the activation of a solar‐driven synthetic cascade by co‐expressing the NADPH‐dependent imine reductase responsible for the generation of precious chiral amines. It is shown that the addition of a diffusing redox mediator is essential for maximizing cell performance. These results present a promising route toward the development of semi‐artificial photosynthetic processes in living cells.

Conversion of Photoluminescence Blinking Types in Single Colloidal Quantum Dots.

Almost all colloidal quantum dots (QDs) exhibit undesired photoluminescence (PL) blinking, which poses a significant obstacle to their use in numerous luminescence applications. An in-depth study of the blinking behavior, along with the associated mechanisms, can provide critical opportunities for fabricating high-quality QDs for diverse applications. Here the blinking of a large series of colloidal QDs is investigated with different surface ligands, particle sizes, shell thicknesses, and compositions. It is found that the blinking behavior of single alloyed CdSe/ZnS QDs with a shell thickness of up to 2nm undergoes an irreversible conversion from Auger-blinking to band-edge carrier blinking (BC-blinking). Contrastingly, single perovskite QDs with particle sizes smaller than their Bohr diameters exhibit reversible conversion between BC-blinking and more pronounced Auger-blinking. Changes in the effective trapping sites under different excitation conditions are found to be responsible for the blinking type conversions. Additionally, changes in shell thickness and particle size of QDs have a significant effect on the blinking type conversions due to altered wavefunction overlap between excitons and effective trapping sites. This study elucidates the discrepancies in the blinking behavior of various QD samples observed in previous reports and provides deeper understanding of the mechanisms underlying diverse types of blinking.

Insight into the effect of synthesis parameters on the properties of graphene quantum dots for theranostic application

Ultra-small size and tunable optical properties of graphene quantum dots (GQDs) make them potentially suitable for theranostic applications. This investigation focuses on the effect of process parameters for the synthesis of GQDs of desirable optical properties for biomedical applications. The effect of the raw materials (graphene oxide sheets, glucose, and starch), reaction temperature (170 to 200 °C), and reaction time (3 to 6 h) was investigated on GQDs prepared through hydrothermal treatment. The dispersion of GQDs was characterized using dynamic light scattering (DLS), UV–visible, fluorescence, Raman, and X-ray photon spectroscopic techniques. The effect of the solution temperature and pH on the fluorescence properties of GQDs was also studied. The small hydrodynamic diameter (8.57 ± 1.47 nm) was observed with GQDs prepared from glucose using hydrothermal treatment time of 4 h at 190 °C (GQDs-D). The GQDs-D showed blue fluorescence (λem= 460 nm) with a quantum yield (QY) 67.09 ± 1.25%. The fluorescence characteristic of the GQDs was unchanged up to 6 months during storage at room temperature. GQDs-D revealed their antioxidant nature with a DPPH scavenging activity of 15.08 ± 2.07%. Despite having relatively low DPPH scavenging activity, excellent hemocompatibility (0.23 ± 0.04%) and colloidal stability against bovine serum albumin (BSA) showed GQDs-D as a safe nanocarrier for theranostic application. This was further substantiated with circular dichroism (CD) spectroscopy, which exhibited a preserved α-helical structure of BSA by GQDs-D. High-resolution transmission electron microscopic image of GQDs-D showed an average particle size of 5.70 nm and homogeneous particle distribution between 2–8 nm. Conclusively, all the results revealed the potential of GQDs-D for theranostic application.

Growth of Medium-Sized InP Quantum Dots with High Photoluminescence Efficiency and Enhanced Stability

This study introduces medium-sized core/shell InP quantum dots (QDs) with high photoluminescence (PL) efficiency and remarkable material stability. The incorporation of a ZnSe interlayer between the core and the thicker outer ZnS shell enhances both the optical performance and material stability. When further increasing the S/Se ratio to synthesize larger QDs with a thicker ZnS layer, optical performance significantly declines despite the improvement in stability. To achieve QDs with superior optical performance and stability, we controlled the S/Se ratio variation during shell growth and examined its impact on the structure, morphology, and size of InP QDs. Our approach resulted in medium-sized InP/ZnSe/ZnS QDs with tunable wavelengths (606-630 nm), PL quantum yields (PLQY) > 90%, full width at half maximum (FWHM) values < 40 nm, and enhanced material stability.Keywords: indium phosphide (InP), quantum dots (QDs), high efficiency and stability, S/Se ratio of shell, medium-size quantum dots, stainless steel reactor Figure 1