Low Luminescence Intensity Research Articles

Maximizing Upconversion Luminescence of Co-Doped CaF₂:Yb, Er Nanoparticles at Low Laser Power for Efficient Cellular Imaging.

Upconversion nanoparticles (UCNPs) are well-reported for bioimaging. However, their applications are limited by low luminescence intensity. To enhance the intensity, often the UCNPs are coated with macromolecules or excited with high laser power, which is detrimental to their long-term biological applications. Herein, we report a novel approach to prepare co-doped CaF2:Yb3+ (20%), Er3+ with varying concentrations of Er (2%, 2.5%, 3%, and 5%) at ambient temperature with minimal surfactant and high-pressure homogenization. Strong luminescence and effective red emission of the UCNPs were seen even at low power and without functionalization. X-ray diffraction (XRD) of UCNPs revealed the formation of highly crystalline, single-phase cubic fluorite-type nanostructures, and transmission electron microscopy (TEM) showed co-doped UCNPs are of ~12 nm. The successful doping of Yb and Er was evident from TEM-energy dispersive X-ray analysis (TEM-EDAX) and X-ray photoelectron spectroscopy (XPS) studies. Photoluminescence studies of UCNPs revealed the effect of phonon coupling between host lattice (CaF2), sensitizer (Yb3+), and activator (Er3+). They exhibited tunable upconversion luminescence (UCL) under irradiation of near-infrared (NIR) light (980 nm) at low laser powers (0.28-0.7 W). The UCL properties increased until 3% doping of Er3+ ions, after which quenching of UCL was observed with higher Er3+ ion concentration, probably due to non-radiative energy transfer and cross-relaxation between Yb3+-Er3+ and Er3+-Er3+ ions. The decay studies aligned with the above observation and showed the dependence of UCL on Er3+ concentration. Further, the UCNPs exhibited strong red emission under irradiation of 980 nm light and retained their red luminescence upon internalization into cancer cell lines, as evident from confocal microscopic imaging. The present study demonstrated an effective approach to designing UCNPs with tunable luminescence properties and their capability for cellular imaging under low laser power.

Co-doped NaYF4:Yb/Er/Tm upconversion luminescent coating to enhance the efficiency of photovoltaic cells.

The use of upconversion luminescent materials to broaden the utilization range of the solar spectrum to enhance the efficiency of photovoltaic cells offers a promising and sustainable approach. However, the low luminescence intensity and easy quenching of upconversion luminescent materials bring serious challenges to the practical application. Herein, a novel method using Co2+ ion doping to regulate the luminescence properties of NaYF4:Yb/Er/Tm is proposed. NaYF4:Yb/Er/Tm microcrystals doped with different proportions of Co2+ ions are prepared and used as coatings on the surface of photovoltaic cells. Co2+ ions regulate the crystallinity and size of the NaYF4:Yb/Er/Tm microcrystals and reduce the crystal field symmetry of the activator (Er3+ and Tm3+) ions. The results show that the emission intensity of green and red light is 18.19% and 83.24% times higher than that of undoped Co2+ ion materials, respectively. Besides, the efficiency of photovoltaic cells after coating Co2+ ion doped NaYF4:Yb/Er/Tm is 2.08% higher than that of the uncoated one. This work underscores the importance of Co2+ ion doping to improve and enhance the luminescence properties of NaYF4:Yb/Er/Tm, to further enhance the efficiency of photovoltaic cells.

Improving luminescence characteristics of Ni2+ doped CsPbX3 (X = Br/I, I) quantum dots in borogermanate glass for wide color gamut display

For wide gamut backlight display application, main problems of CsPbX3 (X = Br/I, I) quantum dots (QDs) glasses as red emission materials are too long emission wavelengths, low luminescence intensity and worse uniformity. The full width at half maximum (FWHM) and decay time should also be considered. Here, Ni2+ doped CsPbX3 (X = Br/I, I) QDs in borogermanate glasses have been successfully fabricated by melt quenching and heat treatment. Transmittance, absorbance, photoluminescence (PL), PL excitation (PLE), PL decay and PL temperature characteristics are measured. By Ni2+ doping in the CsPbX3 (X = Br/I, I) QDs glasses (QDGs), PL intensity is significantly improved to higher level of 106–107 counts (enhanced by 1.6–1.7 times). The peak wavelength is adjusted to suitable range of 630–650 nm by double anion CsPb(Br/I)3 QDs. The uniformity is greatly improved by using suitable composition and concentration of CsPbX3 (X = Br/I, I) QDs. In addition, the FWHM of 32–46 nm is sufficiently narrow. The PL decay shows sufficiently short lifetime of less than 100 ns. The PL temperature dependence fitting shows large exciton binding energy 376–400 meV. For wide color gamut display application, we have used three primary colors with the standard blue, green and red lights in NTSC standard, and the red light has been replaced by using perovskite CsPbX3 (X = Br/I, I) QDGs. For the perovskite CsPbX3 (X = Br/I, I) QDGs emitted at 667 nm and 644 nm, the color gamut area has been increased by 11% and 9%, respectively. The results indicate that the red light QDG materials can be applied to wide color gamut display.

A porous Eu-PTA/Tb-SSA/ZrO2/ZnZrO3 light color adjustable phosphor: Luminescent property and application of warm white LED

Light emitting diode (LED) is the fourth generation lighting source, but it has some shortcomings such as complex chip packaging process and the unbalanced light color of phosphor in long-time application. In this study, a kind of Eu-terephthalic acid/Tb-sulfosalicylate/ZrO2/ZnZrO3 (Eu-PTA/Tb-SSA/ZrO2/ZnZrO3) phosphor with warm white light emission properties was prepared, and the warm white light LED (w-WLEDs) was successfully prepared by encapsulating Eu-PTA/Tb-SSA/ZrO2/ZnZrO3 phosphors together with 270 nm UV-chip. The ZrO2/ZnZrO3, Tb-SSA/ZrO2/ZnZrO3 and Eu-PTA/ZrO2/ZnZrO3 samples show blue emission, green emission and red emission under deep ultraviolet (UV, 270 nm) excitation, respectively. The Tb-SSA and Eu-PTA are co-doped into ZrO2/ZnZrO3 matrix with blue emission to achieve the warm white light emission, and the light color can be adjusted by controlling the doping amount of Eu3+ and Tb3+. Through the excitation method of single-component phosphor by the single chip, the complex chip packaging process of w-LED can be solved. By doping rare earth organic complexes into porous ZrO2/ZnZrO3 matrix, the problems of the light color unbalanced of phosphor and the low luminescence intensity of rare earth doped metal oxides composites can be solved.

Effect of phosphorus doping on the luminescence intensity of Si-NC in SiO/Si multilayers.

The application of silicon nanocrystals (Si-NC) is somewhat limited due to their low luminescence intensity. Therefore, it is of interest to investigate methods for enhancing the luminescence intensity of Si-NC. In this study, phosphorus (P)-doped Si-NC with two different doping methods were prepared by electron beam thermal evaporation: in-situ doping (during synthesis) and ex-situ doping (after synthesis). The photoluminescence (PL) intensity and crystallinity of Si-NC can be enhanced through phosphorus doping. Moreover, a comparison between two different methods of Si-NC doping reveals that the luminescence intensity of in-situ P-doped Si-NC is superior to that of ex-situ P-doped Si-NC, which is increased by an order of magnitude compared to the PL intensity of undoped Si-NC.

Crystal Field Engineering of Pr-Activated Gehlenite with Near Golden Ultraviolet C Emission for 100% Sterilization Efficiency.

Ultraviolet C (UVC) sterilization has the advantages of high efficiency, broad spectrum, and no secondary pollution. However, the emission wavelength of UVC phosphors still suffers from a large deviation from the golden sterilization wavelength of 265 nm and a low luminescence intensity. Herein, we report UVC emission near the golden sterilization wavelength as well as a long afterglow through crystal field engineering, which can lead to 100% sterilization efficiency. Combined with theoretical calculation and experimental studies, substitution of Ca2+ with large-sized Sr2+ could obtain slight expansion and distortion of cationic sites, resulting in a decrease in crystal field intensity and blue shift of Ca1.5Sr0.5Al2SiO7:1%Pr3+, and produce near golden UVC emission. Ca1.5Sr0.5Al2SiO7:1%Pr3+ phosphor can effectively inactivate Staphylococcus aureus within 10 min, showing more efficiency than the traditional mercury lamp. This work provides an effective solution for the design and preparation of UVC phosphors using crystal field engineering toward near golden UVC emission.

Aggregation-induced emission photosensitizer/bacteria biohybrids enhance Cerenkov radiation-induced photodynamic therapy by activating anti-tumor immunity for synergistic tumor treatment

Cerenkov radiation-induced photodynamic therapy (CR-PDT) gets rid of the limited tissue penetration depth of the external light source and provides a feasible scheme for the PDT excited by the internal light. However, due to the low luminescence intensity of Cerenkov radiation, CR-PDT alone cannot effectively inhibit tumor growth, curbing the potential clinical translation of CR-PDT. Herein, we reported an AIE-PS/bacteria biohybrid (EcN@TTVP) composed of Escherichia coli Nissle 1917 (EcN) loaded with aggregation-induced emission photosensitizer (AIE-PS) termed TTVP, which enhanced CR-PDT by activating anti-tumor immunity for synergistic tumor treatment. The preferential tumor-colonized EcN@TTVP and radiopharmaceutical 18F-fluorodeoxyglucose (18F-FDG) were administered sequentially to enable them to co-enrich in the tumor site, thereby triggering CR-PDT and promoting immunogenic tumor cell death. Most importantly, EcN acting as immunoadjuvants enhanced the maturation of dendritic cells (DCs) and priming of cytotoxic T cells (CTLs). Therefore, under the synergistic treatment of CR-PDT and immunotherapy, AIE-PS/bacteria biohybrids resulted in either efficient tumor remission or a survival prolongation in tumor-bearing mice, which presented significant advantages over single CR-PDT. Remarkably, no obvious toxic effects were observed during the treatment. In this study, we proposed a synergistic therapeutic strategy based on EcN@TTVP for combined CR-PDT and immunotherapy against tumors. Moreover, this strategy may have great potential in clinical translation and provide references for deep-seated tumor treatment. Statement of significancePDT is restricted due to the shallow penetration depth of light into tumor tissues. Using CR as the excitation light source for PDT can overcome the aforementioned issue and greatly expand the application of PDT. However, the low efficacy of single CR-PDT limits further its applications. Therefore, the design and development of feasible strategies to improve the efficacy of CR-PDT are of immediate importance. Introducing probiotics to our study can be used not only as tumor-targeting carriers of photosensitizers but also as immunoadjuvants. Under co-stimulation by immunogenic tumor cell death triggered by CR-PDT and probiotics acting as immunoadjuvants, anti-tumor immune responses were effectively activated, thus remarkably enhancing the efficacy of CR-PDT.

Tailoring Z-Scheme heterojunction photocatalyst g-C3N4 nanosheet/Rhenium tricarbonyl complex for converting CO2 to CO with high efficiency and selectivity

Visible-light-driven photocatalyst g-C3N4/ReC converting CO2 to fuels is a promising technology to solve climate change and energy demand. The redshift of the absorption region and the low luminescence intensity of g-C3N4/ReC contributes to enhance the photocatalytic activity. The CO formation and selectivity reach the highest TONCO = 28.81 at 210 min and 94.7%, respectively. The photocatalytic efficiency is enhanced 5.6 times compared ReC. The g-C3N4/ReC firstly combines of a semiconductor and ReC complex, contributes to the design of novel visible-driven photocatalytic systems working under low-intensity visible-light irradiation.

SPECIFIC FEATURES OF PULSED CATHODOLUMINESCENCE UNDER EXCITATION BY NANOSECOND AND SUBNANOSECOND ELECTRON BEAMS

Pulsed cathodoluminescence of crystals and ceramics was excited by runaway electron beams with a duration of 10–12 ps and electron beams with a duration of 2 ns generated in a vacuum diode. The results of comparative studies of their pulsed cathodoluminescence parameters are presented. The luminescence spectrum and the decay kinetics of the bands are shown to coincide in both cases. When excited by a beam of runaway electrons, a lower luminescence intensity is observed. Also in some cases a delay in the appearance of luminescence relative to the onset of the electron beam action was found. The mechanism for the delay appearance under excitation by a runaway electron beam is associated with the process of luminescence rise.

Identification of the causative agent of canine babesiosis in the North of Kazakhstan.

Canine babesiosis is a common disease in the northern part of the Republic of Kazakhstan, in particular in the Kostanay region. In recent years, a large number of cases of the disease with a variety of clinical symptoms have been registered. The purpose of the study was to monitor the spread, characterization, and identify the Babesia species involved of Babesia species in ticks and blood of dogs in the Kostanai region. The research work began in 2017 with the study of the spread of babesiosis in dogs in the Kostanay region according to the reports of veterinary clinics. The collection of ticks from the territory and from dogs was carried out in 2017-2021. As a result of the research work, the presence in the city and some areas of the Kostanay region of two species of ixodid Dermacentor reticulatus and Dermacentor marginatus, was established. Of these, one species was identified in dogs, which serves as a carrier of canine babesiosis-D. reticulatus. In all 31 DNA samples from the blood of dogs diagnosed with babesiosis, a fragment of the 18S rRNA gene was amplified. The nucleotide sequence was obtained for 30 samples (96.8%), in one sample a low luminescence intensity of a specific PCR product was observed. Two Babesia canis haplotypes were distinguished on the basis of two nucleotide substitutions (GA→AG) observed in the sequences of the 18S rRNA gene. In conclusion, the results of this study provide insight into the distribution of B. canis haplotypes in dogs in the Kostanay region, and canine babesiosis is caused solely by the large Babesia species B. canis.

Facile synthesis and enhanced luminescence properties of Cu2-xS@YF3:Yb–Er core-shell nanoparticles

Up-converting luminescent nanoparticles (UCNPs) have been arousing increasing attention in biomedical imaging because of their long-life emission and concomitant benefits (e.g., zero-autofluorescence background, low toxicity). However, the further development on the application has been limited by the low luminescence efficiency and intensity of UCNPs. Herein we report the design principle, synthesis route, and luminescence properties of core-shell structured Cu2-x[email protected]3:Yb–Er nanoparticles with strong luminescent property (red emission). The design principle leverages on the plasmon-enhanced localized electric fields effect of the interface of Cu2-xS and YF3:Yb–Er nanoparticles and photo-thermal effect of Cu2-xS. This strategy could enhanced luminescence properties of YF3:Yb–Er nanoparticles. The as-prepared Cu2-x[email protected]3:Yb–Er nanoparticles possessed stronger luminescent property (red emission) than individually dispersed YF3:Yb–Er nanoparticles. And the nanoparticles presented a dramatic red-shift that was due to the growth of YF3:Yb–Er on the Cu2-xS surface. The research supplies an insight on the development of nonmetallic plasmon-sensitized luminescent materials, and hopefully it could promote them application in the diagnosis and treatment of cancer.

Effect of UV Irradiation on Optical Properties of Water-Based Synthetic Zinc Selenide Quantum Dots

ZnSe quantum-dots were synthesized in an aqueous system and UV irradiation was introduced as a post-treatment process. The synthesis temperature was varied from 25 oC to 90 oC, and the surface of the nano powder was stabilized using different ligands such as glutathione (GSH), 3-mercaptopropionic acid (MPA) and thioglycolic acid (TGA). Then, the effect of UV irradiation on the structure and the absorption/ emission properties of the nano powder were investigated. As the UV light was irradiated, the PL intensity of the quantum dots increased. UV irradiation for 16 h increased the PL intensity of the synthesized quantum dots at room temperature to the level of those at 90 oC. Particle aggregation was not found with UV irradiation of at least 24 h. XRD patterns confirmed that the UV irradiation released sulfur from the GSH, inducing the formation of the ZnSe/ZnS composite-typed nano powders. The luminescence characteristics of the GSH or TGA-added quantum dots were enhanced by UV irradiation regardless of temperature, while MPA-added quantum dots were not significantly affected by UV irradiation. The post-treatment process with UV irradiation showed the possibility that even ZnSe quantum dots, which are synthesized at low temperature and have low luminescence intensity, can have luminescence characteristics comparable to those of high-temperature synthesis.

One‐Pot Preparation of Binary Photocatalyst ZnO/g‐C3N4 Nanosheets with Enhanced Photocatalytic Activity in Dye Degradation

AbstractA novel binary ZnO/g‐C3N4 nanosheets (ZCN)‐X (X=10, 20 and 30 wt% of ZnO) composites were prepared by a simple hydrothermal method. The properties of the samples were characterized by XRD, FT‐IR, SEM, UV‐vis, PL, XPS and electrochemistry, and the photodegradation effect of the samples on MO were evaluated. The FT‐IR spectra revealing that the conjugated system between g‐C3N4 and ZnO was generated. The UV‐vis diffuse reflectance spectra showed that the introduction of CNNs reduces the band gap of binary composites and broadens the visible light absorption range of the samples. The fluorescence analysis results suggested that the conjugated system between g‐C3N4 and ZnO was generated. The phtotcatalysis results showed that ZCN‐20 has strong photodegradation activity and lower luminescence intensity. After irradiation for 120 min under visible light, it gives a degradation rate of 98.5 % with good stability. The construction of heterojunction between CNNs and ZnO nanoparticles accelerates electron transfer and inhibits the recombination of photogenerated electron hole pairs, and the synergistic effect of CNNs and ZnO greatly enhanced the photocatalytic performance of samples.

Silver nanoparticle enhanced luminescence of [Ru(phen)3]Cl2 for thermal imaging application

The temperature dependent photoluminescence of temperature sensitive paint (TSP) makes it an attractive candidate for infrared (IR) thermal imaging, but its low luminescence intensity and poor photostability hinder its extensive use in infrared detectors. Herein, a novel complex luminophore of AgNPs/[Ru(phen)3]Cl2/PVDF was designed to fabricate a thermal imaging device with improved sensitivity and signal-to-noise ratio. It is found that the localized surface plasmon resonance (LSPR) of silver nanoparticles (AgNPs) could enhance the local intensity of the excitation light, consequently an increase in the luminescence intensity of neighboring luminophore can be achieved. Thus, not only the fluorescence intensity of the obtained sensor array is enhanced, but the temperature sensitivity is also improved to −4.5%/K at 20 °C, which increased by 25% compared to that of the blank film without AgNPs addition. Furthermore, the detector array is used for IR thermal imaging, which can successfully obtain the thermal images of observation object at room temperature. The minimal detectable temperature is as small as about 313 K.

Lifetime oxygen sensors based on block copolymer micelles and non-covalent human serum albumin adducts bearing phosphorescent near-infrared iridium(III) complex

In the present report we describe block copolymer micelles based on either poly(dimethylsiloxane-block-ethylene glycol), PDMS15-b-PEG110, or poly(ε-caprolactone-block-ethylene glycol), PCL45-b-PEG110, loaded by the near-infrared (NIR) phosphorescent iridium(III) complex (Ir1) of [(N^C)2Ir(N^N)]+ type, where N^C is cyclometalating 6-(benzo[b]thiophen-2-yl)phenanthridine ligand and N^N is a bidentate diimine (1-(pyridin-2-yl)-1H-1,2,3-triazol-4-yl)methyl benzoate) ligand. We also compare both types of phosphorescent micelles ([email protected]15-b-PEG110 and [email protected]45-b-PEG110) with aggregate-free non-covalent adducts of Ir1 with human serum albumin ([email protected]). Finally, we evaluate the applicability of all these phosphorescent nanoparticles for oxygen sensing by phosphorescence lifetime imaging (PLIM). Both studied block copolymer micelles are compact (hydrodynamic radii less than 20 nm) and solubilize Ir1 up to at least 8 wt.% with almost 100% loading efficiency while preserving the complex phosphorescence. In contrary, the loading efficiency of Ir1 in [email protected] does not exceed 27% resulting in highest possible loading of 0.35 wt.% and much lower luminescence intensity. Lifetime measurements revealed that [email protected]45-b-PEG110 micelles are the best in protecting Ir1 from interactions with the components of physiological media while [email protected]15-b-PEG110 demonstrates the highest lifetime response towards oxygen variations (τdeg/τaer = 2.5), the fastest internalization into Chinese hamster ovary (CHO-K1) cell monolayers, and the strongest intracellular PLIM signal. Though neither system showed ideal combination of desired properties, the present study clearly demonstrates high potential of phosphorescent block copolymer micelles in PLIM oxygen sensing.

Optimized Multimetal Sensitized Phosphor for Enhanced Red Up-Conversion Luminescence by Machine Learning.

In this research, machine learning including the genetic algorithm (GA) and support vector machine (SVM) algorithm is used to solve the "low up-conversion luminescence (UCL) intensity" problem in order to find the optimal phosphor with enhanced red UCL emission using multielement K/Li/Mn metal modulation. Compared with the first generation of phosphors, the best phosphors' fluorescence intensity occurs in the third generation optimized by the GA, with a stronger brightness (4.91-fold), a higher relative quantum yield (6.40-fold), and an enhanced tissue penetration depth (by 5 mm). The single and multiple dopants effect on the upconversion intensity of K+Li+Mn sensitizers is also studied: the intensity increases first and then decreases with the increase of Yb/Er/K+Li+Mn content, and the optimized K+Li+Mn concentration is 6.03%. In order to confirm the stability of the brightness optimization by the GA, a batch of phosphors was synthesized with the same element proportion, and the similarity of fluorescence intensity of two batches of phosphors was evaluated by the SVM algorithm with the classification accuracy index. Finally, the optimized phosphor was used for bioimaging and phosphor-LED.

Phonon coupling and shallow defects in CuInS2

$\mathrm{Cu}(\mathrm{In},\mathrm{Ga}){\mathrm{S}}_{2}$ is an emerging material for solar cells, reaching already efficiencies above 15%. For any solar cell material, it is essential to understand the recombination processes and doping behavior of its defects. Therefore, in this work, we present a detailed photoluminescence and admittance investigation of polycrystalline $\mathrm{CuIn}{\mathrm{S}}_{2}$ thin films to study the shallow intrinsic defects. We find evidence for two acceptors, 105 and 145 meV from the valence band, their predominance depending on the Cu excess, plus one donor, 30 meV from the conduction band. The high crystalline and electronic quality of our samples allows the detection of low intensity luminescence peaks. Based on these emissions we can analyze the phonon coupling of the observed defects and show that an emission previously attributed to a second donor is in fact a phonon replica of the first donor-acceptor transition.

The boron effect on low temperature luminescence of SrAl2O4:Eu, Dy

Temperature dependence of the afterglow of persistent luminescence material SrAl2O4:Eu,Dy is a major problem for outdoor low temperature applications. Therefore this publication deals with tailoring the material for better outdoor use by exploring the second mechanism, that is involved in the afterglow – charge tunnelling from the trapping center to the luminescence center. Structure, morphology, emission and thermally stimulated luminescence properties have been measured for SrAl2O4:Eu,Dy samples with different added boron percentage. The results indicate a change in morphology of the samples with increasing boron concentration, as well as a change in afterglow times. The low temperature luminescence intensity and afterglow time dependence of boron addition turns out to be different from the room temperature luminescence intensity and afterglow time dependence from boron concentration. Boron addition in necessary amount plays a key role to creating trapping centers in the material that are located spatially close to the luminescence center thus making the material afterglow possible even in low temperatures.

Разнолигандные комплексные соединения европия (III) с o-метоксибензойной кислотой и фосфорсодержащими нейтральными лигандами

The luminescent coordination multi-ligand compounds of europium (III) with o-methoxybenzoic acid and island-containing phosphorus-containing neutral ligands of the composition Eu (MOBA) 3 • 3Н2О and Eu (MOBA) 3 • L, where MOBA is o-methoxybenzoic acid, D is hmpa (D hexamethylphosphoric triamide), tppo (triphenylphosphine oxide), Et6pa (hexaethylphosphotriamide). The composition, structure, and thermal properties of complex multi-ligand compounds of europium (III) were studied. It was shown that during thermolysis, detachment of a neutral ligand molecule occurs in one stage with an endothermic effect, complex compounds are stable up to 280 С.Based on the data of IR spectroscopy, it was found that in the europium (III) o-methoxybenzoates, the o-methoxybenzoic acid is coordinated to the europium (III) o-methoxybenzoic ion in a bidentate manner. The low luminescence intensity of multi-ligand europium (III) compounds is explained by the inefficient transfer of electronic excitation energy from o-methoxybenzoic acid and phosphorus-containing neutral ligands to the europium ion.

Structure and Photoluminescence Properties of Hybrid Nanocomposites on the Base of PP/PbS/CdS

In given paper, were studied optical properties of nanocomposites obtained on base of PP + PbS/CdS with different concentration. The UV–Vis spectral analysis indicated that the optical band gap of the system was decreases with increasing of concentration of semiconductor nanoparticles inside the polymer. This can be explained by increasing of size of nanoparticles due to agglomeration of nanoparticles with increasing of concentration. SEM analysis of PP + PbS/CdS based nanocomposites showed that particle size in PP + 3% PbS/CdS, PP + 5% PbS/CdS, and PP + 15% PbS/CdS nanocomposites was the range of 5–10 nm, 12–18 nm, and 18–34 nm in respectively. At the same time, were investigated luminescence spectra of nanocomposites with different concentrations obtained on the base of PP + PbS/CdS. It has been established that the highest luminescence intensity is observed in nanocomposites PP + 3% PbS/CdS. This can be explained by the fact that in this concentration the luminescent centers are more active and more optimal structures are formed. At the same time, low luminescence intensity in PP + 15% PbS/CdS nanocomposites can be explained by reduction of the luminescence surface and weakening of activity of centers due to the growing size of particles by agglomerating with increasing of concentration.