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CZTS (Cu2ZnSnS4), a P-type semiconductor with a direct bandgap (1.2–1.7eV), earth-abundant, non-toxic, and has a large absorption coefficient makes it extremely useful in optoelectronics and light-harvesting applications. In this work, CZTS is prepared by an ingenious, cost-effective colloidal route using the ‘hot-injection’ method with the usage of different ligands. The XRD and Raman spectroscopy shows the single-phase highly crystalline CZTS nanoparticles with kesterite structure. The TEM results show that the size of CZTS nanoparticles is about 2–5 nm and monodispersity is confirmed by DLS (Dynamic Light Scattering). FTIR confirms the presence of different ligands used in CZTS preparation. The Uv–vis absorption shows the direct bandgap of 1.5–1.7eV. The contact angle study shows the hydrophobic nature of as-synthesized CZTS nanoparticles which were further ligand exchanged with l -cysteine hydrochloride to make it hydrophilic to study the photocatalytic degradation activity of organic pollutants and industrial waste in the water. The photocatalysis experiments were performed under two conditions: (i) under bare sunlight (Intensity ∼ 900 W/m2) (ii) focussing the sample under the sunlight via converging lens (1800 W/m2). The photocatalytic efficiencies were then compared and the best photocatalytic efficiency achieved under sunlight was 98.4% for organic pollutants and 75% for industrial waste via converging lens while the corresponding efficiencies with bare sunlight were 98.1% and 73% respectively. To the best of the author’s knowledge, a rapid and highly efficient photocatalysis of CZTS NPs employing a converging lens for water-remediation without the usage of noble & transition-metals has been reported for the first time.

An exemplary vision to understand the fundamental role of metal-doped multi-components system such as Au/Ag doped CZTS (Cu

In this article, the beneficial effect of surface passivation rendered by the amalgamation of co-ordinating tri-n-octylphophine (TOP), oleylamine (OLA), and oleic acid mixture on the structural and optoelectronic properties of lead selenide (PbSe) quantum dots (QDs) (~6–20 nm) and its respective poly(3-hexylthiophene) (P3HT) polymer: PbSe composites has been demonstrated. Here, OLA ligand is found to play a major role in the nucleation and growth mechanism and hence control of the size distribution of the resultant PbSe QDs. The superior quality of the OLA-passivated PbSe QDs can be attributed to its better homogeneity, colloidal and photostability, which it imparts to its respective polymer: PbSe composites as compared to the corresponding OA-passivated PbSe QDs. The role of post-synthesis ligand exchange/removal has been envisaged to facilitate efficient charge transport in hybrid composites and has been modeled pictorially. Accordingly, P3HT: PbSe (OLA) composites exhibit significant PL quenching and hence higher current and better charge transfer characteristics as compared to their OA-counterparts. An exhaustive structural, optical and electrical investigations as corroborated by various complimentary techniques (TEM/SEM, XRD, NMR, FTIR, NIR-Absorption, PL, XPS, and I-V) have resulted in some significant findings wherein the effective stabilizing and etching properties with an optimum binding capability of OLA ligands to PbSe surface are found to be imperative for its effective utilization in hybrid composite photovoltaic devices. The superior morphology, optical properties, and higher stability of OLA-capped PbSe QDs can aid in the proper understanding of efficient charge separation and transport in hybrid organic–inorganic nanocomposites solar cells based on colloidal PbSe nanocrystals.

We report the fabrication and characterization of varying concentration (x) of copper (Cu)-doped TiO2 nanocomposites [Cu( x )TiO2(1- x )] exploring the photocatalytic properties for sunscreen appli...

BackgroundSARS-CoV-2 is a viral pathogen causing life-threatening disease in human. Interaction between spike protein of SARS-CoV-2 and ACE2 receptor on the cells is a potential factor in the infectivity of a host. The interaction of SARS-CoV-2 spike receptor-binding domain with its receptor - ACE2, in different hosts was evaluated to understand and predict viral entry. The protein and nucleotide sequences of ACE2 were initially compared across different species to identify key differences among them. The ACE2 receptor of various species was homology modeled (6LZG, 6M0J, and 6VW1 as a reference), and its binding ability to the spike ACE2 binding domain of SARS-CoV-2 was assessed. Initially, the spike binding parameters of ACE2 of known infected and uninfected species were compared with each Order (of animals) as a group. Finally, a logistic regression model vis-a-vis the spike binding parameters of ACE2 (considering data against 6LZG and 6M0J) was constructed to predict the probability of viral entry in different hosts.ResultsPhylogeny and alignment comparison did not lead to any meaningful conclusion on viral entry in different hosts. Out of several spike binding parameters of ACE2, a significant difference between the known infected and uninfected species was observed for six parameters. However, these parameters did not specifically categorize the Orders (of animals) into infected or uninfected. The logistic regression model constructed revealed that in the mammalian class, most of the species of Carnivores, Artiodactyls, Perissodactyls, Pholidota, and Primates had high probability of viral entry. However, among the primates, African Elephant had low probability of viral entry. Among rodents, hamsters were highly probable for viral entry with rats and mice having a medium to low probability. Rabbits have a high probability of viral entry. In Birds, ducks have a very low probability, while chickens seemed to have medium probability and turkey showed the highest probability of viral entry.ConclusionsMost of the species considered in this study showed high probability of viral entry. This study would prompt us to closely follow certain species of animals for determining pathogenic insult by SARS-CoV-2 and for determining their ability to act as a carrier and/or disseminator.

Metal halide perovskites have shown excellent properties for lighting applications, including high photoluminescence quantum yield (PLQY), compositional tunability, and narrow emission line widths....

Genomics-led researches are engaged in tracing virus expression pattern, and induced immune responses in human to develop effective vaccine against COVID-19. In this study, targeted expression profiling and differential gene expression analysis of major histocompatibility complexes and innate immune system genes were performed through SARS-CoV-2 infected RNA-seq data of human cell line, and virus transcriptome was generated for T-and B-cell epitope prediction. Docking studies of epitopes with MHC and B-cell receptors were performed to identify potential T-and B-cell epitopes. Transcriptome analysis revealed the specific multiple allele expressions in cell line, genes for elicited induce immune response, and virus gene expression. Proposed T- and B-cell epitopes have high potential to elicit equivalent immune responses caused by SARS-CoV-2 infection which can be useful to provide links between elicited immune response and virus gene expression. This study will facilitate in vitro and in vivo vaccine related research studies in disease control., Highlights • SARS-CoV-2 transcriptome construction from RNA-seq data of infected human cell-lines. • T- and B-cell epitopes from SARS-CoV-2 transcriptome • Gene expression profiling of MHC alleles and innate immune system genes

A new self-activated green-yellow emitting Gd2CaZnO5 (GCZO) phosphor was synthesized using solid-state reaction method at high-temperature. XRD analysis confirmed the orthorhombic structure of the sample with the Pbnm space group. SEM micrographs reveal the irregular morphology with micron sized particles. Detailed photoluminescence (PL) analysis revealed that the excitation of the phosphor lies in the UV range (˜377 nm) with the related broad green-yellow emission centered at 530 nm. The broad band emission ranging from ˜450 nm to 650 nm can be attributed to the surface defects and oxygen vacancies. The calculated luminescence decay lifetime for the optimized phosphor was found to be 2.925 μs. Furthermore, the color-coordinate (x, y) were calculated and found to be (0.44, 0.45), which lies in the green-yellow (˜540 nm) region of the electromagnetic spectrum. The values of color coordinates and Color correlated temperature of 3289 K support the synthesized phosphor for the emission of warm white-light. These results perfectly established the suitability of this green-yellow emitting GCZO phosphor for Ultra-Violet Light-Emitting Diodes (LEDs) excited white-LED applications.

The Mn, Al co-doped ZnO samples were synthesized using solid-state reaction method and were annealed in furnace at 300 °C, 600 °C and 900°C temperature. All the samples prepared were investigated in detail for analysis of their structural, morphological, optical, magnetic and electrical behavior. The XRD data confirmed the hexagonal wurtzite structure of pristine, Mn doped and Al, Mn co-doped ZnO. For morphological investigation SEM and TEM techniques were employed. The PL properties of the ZnO:Mn, Al sample revealed emission in the blue region (415–438 nm). Furthermore, IV studies were carried out to examine the conductivity of the ZnO:Mn, Al samples and maximum conductivity was found in the sample with 5% Al doping and annealing temperature 600 °C. The magnetic measurements revealed room temperature ferromagnetic behavior in the optimized ZnO:Mn, Al sample annealed at 600 °C which indicates its suitability for Magneto-Opto Electronic Applications.

Dye-sensitized solar cells (DSSCs) have become the subject matter of significant interest for the research and due to their urge in the field of energy conservation. The safe supply of energy is welfare of human life. However, as an unattainable power-energy conservation source, also depletion of fossil fuels is an unfortunate mandate and, definitely it is imminent. To encounter this critical issue of energy, non-conventional sources of energy have gained lots of attention, especially solar energy because it’s a device that converts light-energy directly to electrical-energy without harming the environment. DSSCs provides a reliable and a cheap alternative for different kinds of Photovoltaics. The spectacle realization of Dye-sensitized-solar-cell is typically relying on photosensitizer (Dye), electrolyte and metal oxide semiconductor. A natural dye has become most credible alternative for such expensive and rare inorganic/chemical sensitizers, due to its lower cost, easy fabrication, eco-friendly and abundance of raw material. Also, DSSC has easily implemented technology with significant efficiency. This review paper enlightens the emergence, operation/fabrication, components and development of DSSCs using natural photo-sensitizers and factors that affect the stability.

Photoactive degradation of textile malachite green (MG), methylene blue (MB) dyes has been permeated on metal oxide TiO2 nanoparticles under sunlight. Semiconductor photocatalysis is a promising method for removal of toxic chemicals from wastewater produced by industry. Due to tunable bandgap, TiO2 among various semiconductor studied mostly. Large band gap (UV active) and recombination of exciton in TiO2 less active in photo degradation. Noble metals such as gold nanoparticles deposited on TiO2 surface increased the optical activity and to shift optical response to visible region. Degradation detail has been carried out by characterisation such as XRD, UV-Vis, PL, TEM, and SEM for MG and MB textile dyes under sunlight irradiation. UV-visible absorption spectra and PL spectra shows that photo-response of as prepared sample is extended from UV to visible region. PL intensity decreases with increases in concentration of Au nanoparticles, decreases in intensity in optical spectra of Au–TiO2 composites shows that charge transfer process dominates. Au–TiO2 plays an essential role in enhancing photocatalytical activity. Decolorization optimization depends on catalyst concentration, Dye concentration, light intensity and, irradiation time.

Costunolides, an important sesquiterpene lactone (STL) isolated from Saussurea lappa, are the major pharmaceutical ingredient of various drug formulations. Identification of the genes and transcriptional regulation of costunolide biosynthesis pathway in S. lappa will propose alternatives for engineering enhanced metabolite biosynthesis in plant. Here, we aimed to unravel the transcription factors (TFs) regulating the costunolide biosynthesis. Comparative transcriptome analysis of root and leaf tissues and transcripts were annotated using various in silico tools. Putative transcription factors were identified using PlantTFDB and TF- gene co-expression network was generated followed by clustering using module based analysis to observe their coordinated behaviour. The module 1 was found to be significant based on its enrichment with major pathway genes. Further, promoter cloning determined the cis acting elements in costunolide synthase (SlCOS1) gene which catalyses the final key step of costunolide biosynthesis. Bioinformatics tools were employed to predict the cis regulatory elements, leading to the identification of MYB family of TFs as an interacting partner of SlCOS1 gene. The present study is the pioneer attempt for TF prediction and elucidation of their regulatory role in costunolide synthesis. This will help in future metabolic engineering of the pharmaceutically important STLs and their yield improvement.

Solar photovoltaic (PV) is empowering, reliable, and ecofriendly technology for harvesting energy which can be assessed from the fact that PV panels with total electricity generation capacity of 505 GW have been installed by the end of 2018. Thin-film solar cells based on copper indium gallium selenide (CIGSe) are promising photovoltaic absorber material owing to an alternative to crystalline silicon (c-Si)-based solar cells because of the huge potential for low-cost solar electricity production with minimal usage of raw materials. The efficiency record of 23.4% was achieved recently in CIGSe solar cells, which was comparable to c-Si solar cells (27.6%). The manufacturing cost of $0.34/W is expected for 15% efficient CIGSe module. The present review article discusses the perspectives of CISe/CIGSe-based thin-film solar cells with the focus on absorber material. Different vacuum and non-vacuum techniques for fabricating these materials are discussed along with the operation of solar cells and their manufacturability. The working mechanism of CIGSe solar cells with the characteristic features of the open-circuit voltage and current density as well as the factors influencing the efficiency in different fabrication techniques are reviewed. Moreover, some strategies toward the improvement of solar cells performance contemplating modified deposition are reviewed. Furthermore, how these strategies can be executed in order to make it cost effective methods is also discussed in detail. Prevailing constrictions for the commercial maturity are deliberated, and future perspectives for improvement at lab as well as industrial scalabilities are outlined.

NBS-LRR comprises a large class of disease resistance (R) proteins that play a widespread role in plant protection against pathogens. In grapevine, powdery mildew cause significant losses in its productivity and efforts are being directed towards finding of resistance loci or genes imparting resistance/tolerance against such fungal diseases. In the present study, we performed genome-wide analysis of NBS-LRR genes during PM infection in grapevine. We identified 18, 23, 12, 16, 10, 10, 9, 20 and 14 differentially expressed NBS-LRR genes in response to PM infection in seven partially PM-resistant (DVIT3351.27, Husseine, Karadzhandal, Khalchili, Late vavilov, O34–16, Sochal) and 2 PM-susceptible (Carignan and Thompson seedless) V. vinifera accessions. Further, the identified sequences were characterized based on chromosomal locations, physicochemical properties, gene structure and motif analysis, and functional annotation by Gene Ontology (GO) mapping. The NBS-LRR genes responsive to powdery mildew could potentially be exploited to improve resistance in grapes.

The article describes in detail the effect of doping Europium (Eu) on magnetic and optical properties of Cr2O3. Undoped and Eu (1–5 mol%) doped Cr2O3 samples were synthesized using solid state synthesis method. The structural, magnetic and optical properties of undoped and Europium (Eu) doped chromium oxide powder were studied by X-ray diffractometer (XRD), vibrating sample magnetometer (VSM) and photoluminescence (PL) measurements. The X-ray diffraction pattern confirms the polycrystalline nature of undoped and Europium (Eu) doped chromium oxide powder. The magnetic measurements revealed decline in magnetism with increasing Eu concentration. With increasing Eu concentration, the visible luminescence of Cr2O3 improved. The study highlighted that Eu as a dopant is not suitable for improving the magnetic properties of Cr2O3.

Silver oxide nanoparticles (Ag2O NPs) are used widely in fuel cells, sensor, antimicrobial activity, analgesics, catalysis, optics, cosmetic and drug delivery. These nanoparticles are synthesized by chemical, physical and green route. In the present study, the (Ag2O NPs) are synthesized by green route as it is environment friendly, less hazardous, inexpensive and also plants used as capping agent have phytochemicals which act as stabilizing agent and reducing agent. Artocarpus Hetrophyllus plant extract is used for the synthesis of Ag2O NPs by natural chemicals. The leaves were washed several times and then grinded in pestle mortar and finally filtered by Whatman filter paper for further reaction with Silver nitrate (AgNO3 salt) as precursor. The reaction mixture is then heated and stirred at 60–80 °C for 60 mins. The temperature, pH and time period of the reaction mixture is very crucial for the formation of Ag2O NPs. The XRD (X-ray diffraction) technique shows the presence of Ag2O NPs crystallized in Face-centered cubic structure which are in well agreement with the JCPDS Card No.004-0783. UV–Vis spectra as recorded in the 200–700 nm wavelength range shows the band absorbance at 517 nm and band gap of Ag2O NPs is 2.1 eV as determined by Tauc’s plot. The FTIR (Fourier transform infrared spectroscopy) spectra shows the presence of functional group absorbance peaks at 3468 cm−1, 2842 cm−1, 1637 cm−1, 1586 cm−1, 1407 cm−1, 1355 cm−1, 766 cm−1 corresponding to OH, CH2, COOH, C C, C C, C H, Ag O groups respectively present in phytochemicals. DLS (Dynamic light scattering) reveals the Hydrodynamic diameter as 212 nm and monodispersity (Polydispersity index

Magnetic impurity in wide bandgap semiconductors incorporate magneto-electro-optical properties. For the vast application and demand of future market devices; Fe-doped ZnO (Fe-ZnO) powders at different Fe doping concentrations were synthesized by solid-state reaction route. 3%Fe-doped ZnO thin films were also grown using solution route as a powder sample of 3%Fe-ZnO was found to be the Room Temperature Ferromagnetic (RTFM). X-ray Diffraction (XRD) patterns showed the increase in secondary phases from single phase wurtzite ZnO structure with increase in Fe concentration. UV-Vis absorption spectroscopy (UV-Vis) showed decrease in bandgap. In Photoluminescence (PL) spectra quenching is observed as Fe3+ ions occupies the photogenerated Zn ion with an increase in doping concentration. SEM analysis revealed the spherical morphology of nanoparticles ranges in 50 nm. Agglomerations of the Fe2+/Fe3+ ions leads to paramagnetism with an increase in Fe doping. Vibrating Sample Magnetometer (VSM) showed that only 3%Fe-ZnO sample was found to be RTFM whereas paramagnetic behavior dominates with the increase in Fe doping concentration. Since, the type of synthesis route adopted doesn’t have a control of physical and chemical property of any material; Rather the choice of dopant (magnetic-Fe) and the host (optical-ZnO) in an optimized ratio can proves to be a single material with magnetic-optical properties. This material as combination of two properties proves to be a potential for spintronic and biosensor-based device applications both in non-medical and medical areas.

Synthesis of titanium dioxide nanoparticles (TiO2 NPs) has been done by sol-gel-hydrothermal colloidal route in two different apparatus; one being simple stainless steel (named as TiO2-B) and other...

Recently, the demand for an accurate and precise determination of the properties of phase change materials (PCM) has increased considerably owing to the dependence of various applications based on latent heat storage (LHS). As reported earlier, PCM has a higher latent heat of fusion and is the cheapest material to store thermal energy. Still, it has poor thermal conductivity and less heat storage retentivity. For this reason, there is a significant interest in PCM-nanoparticles composites because the incorporation of nanoparticles can enhance the thermal properties of PCM. In the present work, TiO2 NPs were synthesized and incorporated with paraffin and sorbitol (PCM) by varying their mass concentration (0, 5, 10, and 20%) to study and compare the thermal properties of NCs. Different characterizations such as X-ray diffraction (XRD), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), and melting temperature testing of nanocomposites by temperature variation method were studied and analyzed. An appreciable decrement in melting point of 19.19, 27.59, 18.57, and 23.89% from 0 to 20% TiO2 concentrations in paraffin and sorbitol was observed from the temperature variation and DSC results, respectively. TGA/DTG results show minimum wt% loss of 57.76% at 316.24 °C and 90.88% at 317.27 °C calculated for 20 and 10% TiO2 concentrations in sorbitol and paraffin, respectively, which corresponds to the thermal stability of NCs. It was verified by both the methods that melting point decreases linearly with an increase in the concentration of NPs in PCM, which further corresponds to the increment in thermal conductivity and thermal storage capacity. Sorbitol exhibits better stability with TiO2 than paraffin as it consists of low strain, less weight loss, and more thermal compatibility. Uncertainty in the determination of the melting point temperature from temperature variation test method and DSC measurements can mainly be ascribed to the difference in the polarity of paraffin/TiO2 and Sorbitol/TiO2 nanocomposites and on the boundary conditions during heating and cooling which markedly affects the dispersion quality of TiO2 nanoparticles within the PCM (paraffin, sorbitol) matrix and these aspects have been modeled pictorially.

Quaternary chalcopyrite, i.e., Cu2ZnSnS4 (CZTS) nanoparticles films have been proposed as a novel matrix system for enzyme-based electrochemical biosensors providing a non-toxic, low-cost alternative for the fabrication of bioelectrodes. The easy tuneability of the band gap of CZTS by varying the cation ratio and size of nanoparticles facilitate to impart desirable electrical properties in the material. Butylamine capped spherical CZTS nanoparticles of size 15–16 nm and band gap 2.65 eV have been synthesized by colloidal hot injection technique. The films of CZTS onto ITO substrates are deposited using dip coating technique, and uricase enzyme have been immobilized onto CZTS films using EDC-NHS binding chemistry. Electrochemical analyses of this bioelectrode revealed that the uricase/CZTS/ITO/glass electrode exhibits good linearity over a wide range of 0–700 μM uric acid concentration with a limit of detection (LOD) of 0.066 µM. The low value of 0.13 × 10−4 M of Michaelis–Menten constant (Km) indicate the enhanced affinity of immobilized enzyme (uricase) towards uric acid. Thus, the present report confirms the promising application of the p-type CZTS thin film matrix for the realization of an electrochemical biosensor.

The biggest problems in today’s World is energy crisis and deteriorating environmental and thus health conditions. The energy crisis arises due to the maximum use of fossil fuels as an energy resource. Also, these are limited and non-renewable resources and are available only for a few coming decades. In the present time, nanomaterials are being used to produce and store solar energy by converting it directly into electrical (photovoltaic applications) or chemical energy (Photocatalytic applications). Recently, quaternary chalcopyrite compounds like Cu2ZnSnS4 (CZTS), Cu2ZnSnSe4 (CZTSe) and Cu2ZnSn(SexS1-x)4 (CZTSSe) seeks attention from scientific community due to their excellent physicochemical properties. These compounds constituents non-toxic Earth-abundant elements making them low-cost material. These are semiconducting materials having tunable band gap ranging from 1.0 to 1.5 eV, and high optical absorption (>104 cm). Owing to their extraordinary physicochemical properties such as good photostability, high carrier mobility, heat resistance, and long diffusion lengths, it also founds its application in a huge and various applications, including chemistry (photocatalysis), biology (biomedicine and biosensors), and energy regimes (photovoltaics) etc. The present chapter discusses the progress regarding the manufacturing technologies, processing, structural and defect details of CZTS nanoparticles for their applications in photovoltaics regime.

In this paper, pure and Fe2O3 (1–5 mol %) doped Cr2O3has been synthesized using a solid-state synthesis method. X-ray diffraction pattern of pure and Fe2O3: Cr2O3 has a similar crystallographic hexagonal phase with space group R-3c and lattice parameter, a = 5.002 A; c = 13.620 A and, a = 4.913 A; c = 13.469 A, respectively; average crystallite size being ∼29.46 nm. Fe3+ incorporation in Cr2O3 lattice leads to the increase in the particle size as Fe3+has larger ionic radii (∼0.67 A) than Cr3+ (∼0.64 A).Both XRD and EDX showed that Fe2O3: Cr2O3 nanoparticles exhibit no impurities phases, confirms the presence of Cr, Fe, and O materials. The Tauc’s plot showed a decrease in optical band gap from 3.10 to 2.95 eV for Fe content of 0 to 5 mol%, respectively. All samples revealed weak ferromagnetic behavior at room temperature. SEM analysis revealed an increase in particle size from16-38 nm. Electrically, at low frequencies, undoped and low concentration of Fe in Fe2O3: Cr2O3 shows high values of dielectric constant. Further, this value decreases continuously with the increase in frequency. The study revealed that 3% Fe2O3: Cr2O3 sample is excellent among all the doping concentrations (1–5 mol%) for magneto-optoelectronic device applications.

Renewable energy resources come in high demand due to the scarcity of conventional energy sources and associated pollutions. However, the inadequacy of solar power in nonsunshine hours gave rise to the need for thermal energy storage, and the stored thermal energy or heat using a storage media can be released during off-peak hours, known as peak shifting. Phase Change Materials (PCM) based thermal energy storage systems perform comparatively well with good efficiency, with other advantages including low weight per unit storage capacity, retrieval or reversible cycles, and ecofriendly ways to reuse natural energy. However, a major limitation of PCM is poor thermal conductivity and diffusivity. Other problems plaguing most PCMs include phase separation, supercooling, corrosion, volume expansion, and leakage during phase transition. Incorporation of nanoparticles that possess a high surface area to volume ratio, controlled volume expansion, reduced reactivity with the external environment, and high heat transfer rate helps PCM to enhance its thermal conductivity. This work focuses on incorporating different wt.% nanoparticles in PCMs and core-shell confinement, and several organic and inorganic shell materials would be adopted to encapsulate PCM core with different nanoporous scaffolds to confine most of organic PCMs. Optimization of the nanoparticle concentration will aim to enhance PCM’s thermal conductivity without compromising the storage capacity of PCMs. Furthermore, the different parameters like nanoparticle concentration, rate of mass flow, thermophysical properties of nanoparticles, and transition temperature have a significant impact on increased thermal conductivity and thermal energy storage capacity, resulting in low power consumption. Owing to their unique properties of absorbing and releasing heat energy, PCMs are useful for customized applications as per demand, mainly for solar heaters and solar coolers to build comfortable living materials.

У роботі наночастинки оксиду олова (SnO2), відпалені при температурах 400, 500 та 600 °C, були підготовлені методом твердотільної реакції. Структурні та оптичні властивості підготовлених наночастинок SnO2 аналізували за допомогою рентгенівського дифрактометра (XRD) та скануючого електронного мікроскопа (SEM). Елементне дослідження було виконано енергетично-дисперсійною рентгенівською спектроскопією (EDAX), інфрачервоною спектроскопією з використанням перетворення Фур'є (FTIR), методами динамічного розсіювання світла (DLS) та поглинання світла в ультрафіолетовому та видимому діапазонах (UV-Vis). Рентгенівська дифрактограма підтверджує чисту тетрагональну структуру рутилу наночастинок SnO2 без будь-якої домішкової фази. SEM зображення відображають утворення нанострижнів при всіх температурах відпалу 400, 500 і 600 °C, тоді як EDAX аналіз підтверджує наявність Sn і O без будь-яких домішок. UV-Vis спектри показують, що ширина забороненої зони підготовлених наночастинок SnO2 спочатку зменшується з 3,44 еВ при температурі 400 °С до 3,03 еВ при 500 °С, а потім збільшується до 3,39 еВ при температурі 600 °С. Спектр FTIR підтверджує наявність зв'язку O–Sn–O разом з одним небажаним піком поглинання. In the present work, nanoparticles of tin oxide (SnO2) annealed at temperatures of 400 °C, 500 °C, and 600 °C were prepared via solid-state reaction method. Structural and optical properties of prepared SnO2 nanoparticles were analyzed by X-ray diffractometer (XRD), scanning electron microscope (SEM), elemental study was performed by energy-dispersive X-ray spectroscopy (EDAX), Fourier transform infrared spectroscopy (FTIR), dynamic light scattering (DLS) and ultraviolet-visible (UV-Vis) absorption characterizing techniques. The X-ray diffraction pattern confirms the pure tetragonal rutile structure of tin oxide nanoparticles without any impurity phase. SEM images depict the formation of nanorods at all annealing temperatures of 400 °C, 500 °C, and 600 °C while EDAX analysis confirms the presence of Sn and O without any impurities. UV-Vis absorption spectra show that the band gap of prepared tin oxide nanoparticles decreases initially from 3.44 eV at 400 °C to 3.03 eV at 500 °C and further increases to 3.39 eV at 600 °C. FTIR spectrum confirms the presence of O–Sn–O bond along with one unwanted absorption peak.

The synthesis of PbSe nanoparticles were carried out by colloidal route using lead acetate as starting material with Oleic acid/TOP as capping agents at the optimized growth temperature. The phase and surface analysis of oleic acid/TOP capped PbSe nanocrystallites were studied in detail in this article. Current-voltage characteristics of pristine and lead selenide quantum dots (PbSe QDs) incorporated in poly(2-methoxy,5-(2′-ethylhexyloxy)-p-phenylenevinylene (MEH-PPV) thin films have been studied at different temperatures (306–125 K) in hole only device configuration, i.e., ITO/poly(ethylene-dioxythiophene):polystyrenesulphonate (PEDOT:PSS)/MEH-PPV/Au and ITO/PEDOT:PSS/MEH-PPV:PbSe/Au. It has been found that the presence of PbSe QDs in MEH-PPV results in the modulation of the charge transport mechanism from dual conduction mechanism, i.e., trap and mobility model to only trap model. It signifies that the traps are becoming shallower due to reduction in trap density from 2×1017 to 1.2×1017 cm−3 as well as trap energy reduces from 74 meV to 62 meV on the incorporation of PbSe QDs.