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1

Quantum dots for temperature sensing

Doskaliuk Natalia, Lukan Yuliana, Khalavka Yuriy

Scientiae Radices

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2023

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Vol. 2, Iss. 2

93--111

EN

Quantum dots are three-dimensional nanoparticles of semiconductors with typical sizes ranging from 2 to 10 nm. Due to the quantum confinement effect the energy gap increase with the size decreasing resulting in size-depended and fine-tunable optical characteristics. Besides this, the energy structure of a quantum dot with a certain size is highly sensitive to environmental conditions. These specific properties open a wide range of applications starting from optical and optoelectronic devices and ending with biosensing and life science. Temperature is one of those parameters influencing strongly on the optical properties of semiconductor nanocrystals, which make them promising materials for temperature sensing, more often using a fluorescent response. Compared to the conventional organic dyes already applied in this field, quantum dots exhibit a set of advantages, such as high quantum yield and photostability, long fluorescence lifetime, higher Stokes shift, and ability to surface functionalization with targeted organic molecules aimed to provide them biocompatibility. In this review, we briefly discuss the properties of II-VI and assumingly less toxic I-III-VI quantum dots, mechanisms of temperature-induced fluorescence response, and the feasibility of their practical application in the field of thermal sensing.

2

Structural, morphological and photoluminescent properties of Nd-coated silicon nanostructures

Mefoued Amine, Mahmoudi Bedra, Benrekaa Nasser, Tiour Faiza, Menari Hamid, Naitbouda Abdelyamine, Manseri Amar, Brik Afaf, Mezghiche Salah, Debbab Moustafa

Opto-Electronics Review

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2023

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Vol. 31, No. 1

art. no. e145096

EN

The structural, morphological and photoluminescent properties of thermally evaporated neodymium oxide (Nd₂O₃) thin films deposited onto nanostructured silicon (Si-ns) are reported. Si-ns embedded in silicon nitride (SiN) thin films are prepared by plasma-enhanced chemical vapour deposition (PECVD). SiN and Nd₂O₃ thin films uniformity and Si-ns formation are confirmed by atomic force microscopy (AFM) and scanning electron microscopy (SEM). The presence of neodymium (Nd), silicon (Si), oxygen (O), and phosphorus (P) is investigated by energy-dispersive spectroscopy (EDS) and secondary ion mass spectrometry (SIMS). Post-annealing SIMS profile indicates an improvement of the homogeneity of activated P distribution in Si bulk. The X-ray diffraction (XRD) combined with Raman spectroscopy and Fourier-transform infrared spectroscopy (FTIR) have been employed to determine amorphous silicon (a-Si), crystalline silicon (c-Si), Nd₂O₃ and SiN phases present in the Nd₂O₃-SiN bilayers with their corresponding chemical bonds. After annealing, a Raman shift toward lower wavenumbers is recorded for the Si peak. XPS data reveal the formation of Nd₂O₃ thin films with Nd-O bonding incorporating trivalent Nd ions (Nd3+). Strong room-temperature photoluminescence is recorded in the visible light range from the Si-ns. Nd-related photoluminescent emission in the near infrared (NIR) range is observed at wavelengths of 1025-1031 nm and 1083 nm, and hence is expected to improve light harvesting of Si-based photovoltaic devices.

3

A probabilistic approach for approximation of optical and opto-electronic properties of an opto-semiconductor wafer under consideration of measuring inaccuracy and model uncertainty

Stroka Stefan M., Heumann Christian, Suhrke Fabian, Meindl Kathrin

Opto-Electronics Review

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2023

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Vol. 31, No. 2

art. no. e145863

EN

This paper presents a probabilistic machine learning approach to approximate wavelength values for unmeasured positions on an opto-semiconductor wafer after epitaxy. Insufficient information about optical and opto-electronic properties may lead to undetected specification violations and, consequently, to yield loss or may cause product quality issues. Collection of information is restricted because physical measuring points are expensive and in practice samples are only drawn from 120 specific positions. The purpose of the study is to reduce the risk of uncertainties caused by sampling and measuring inaccuracy and provide reliable approximations. Therefore, a Gaussian process regression is proposed which can determine a point estimation considering measuring inaccuracy and further quantify estimation uncertainty. For evaluation, the proposed method is compared with radial basis function interpolation using wavelength measurement data of 6-inch InGaN wafers. Approximations of these models are evaluated with the root mean square error. Gaussian process regression with radial basis function kernel reaches a root mean square error of 0.814 nm averaged over all wafers. A slight improvement to 0.798 nm could be achieved by using a more complex kernel combination. However, this also leads to a seven times higher computational time. The method further provides probabilistic intervals based on means and dispersions for approximated positions.

4

Imaging methods of detecting defects in photovoltaic solar cells and modules: a survey

Maziuk Maurycy, Jasińska Laura, Domaradzki Jarosław, Chodasewicz Paweł

Metrology and Measurement Systems

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2023

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Vol. 30, nr 3

381--401

EN

In pursuit of increased efficiency and longer operating times of photovoltaic systems, one may encounter numerous difficulties in the form of defects that occur in both individual solar cells and whole modules. The causes of the occurrence range from structural defects to damage during assembly or, finally, wear and tear of the material due to operation. This article provides an overview of modern imaging methods used to detect various types of defects found in photovoltaic cells and panels. The first part reviews typical defects. The second part of the paper reviews imaging methods with examples of the authors’ own test results. The article concludes with recommendations and tables that provide a kind of comprehensive guide to the methods described, depending on the type of defects detected, the range of applicability, etc. The authors also shared their speculations on current trends and the possible path for further development and research in the field of solar cell defect analysis using imaging.

5

HgCdTe energy gap determination from photoluminescence and spectral response measurements

Murawski Krzysztof, Kopytko Małgorzata, Madejczyk Paweł, Majkowycz Kinga, Martyniuk Piotr

Metrology and Measurement Systems

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2023

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Vol. 30, nr 1

183--194

EN

The temperature dependence of photoluminescence spectra has been studied for the HgCdTe epilayer. At low temperatures, the signal has plenty of band-tail states and shallow/deep defects which makes it difficult to evaluate the material bandgap. In most of the published reports, the photoluminescence spectrum containing multiple peaks is analyzed using a Gaussian fit to a particular peak. However, the determination of the peak position deviates from the energy gap value. Consequently, it may seem that a blue shift with increasing temperature becomes apparent. In our approach, the main peak was fitted with the expression proportional to the product of the joint density of states and the Boltzmann distribution function. The energy gap determined on this basis coincides in the entire temperature range with the theoretical Hansen dependence for the assumed Cd molar composition of the active layer. In addition, the result coincides well with the bandgap energy determined on the basis of the cut-off wavelength at which the detector response drops to 50% of the peak value.

6

Versatile semiconductor quantum dots: synthesis, bioconjugation strategies and application

Poddar M., Khurana S., Bose S., Nayak R.

Archives of Materials Science and Engineering

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2023

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Vol. 121, nr 1

25--32

EN

Purpose: The present work aimed to synthesize organic and inorganic quantum dots (QDs) and discuss their bioconjugation strategies. Design/methodology/approach: We have prepared 3 different QDs, organic (Carbon [CQDs]) and inorganic (Cadmium Sulphide [CdS] and Zinc Mercury Selenide [ZnHgSe]) quantum dots (QDs) and bioconjugation through in-situ and ex-situ route. These QDs have been characterized through UV-Vis spectroscopy and photoluminescence (PL) emission spectra. Their surface functional groups have been identified through Fourier-transform infrared (FTIR) spectroscopy. The bioconjugated quantum dots were tested through PL emission shift, Agarose electrophoresis, and Bradford assay technique. Findings: Successful synthesized QDs, and their bioconjugation has been confirmed through the previously listed characterization techniques. There are distinct differences in their emission peak, FTIR spectroscopy, and Bradford assay, which confirms their successful bioconjugation. Research limitations/implications: These bioconjugated QDs are difficult to filter from their unconjugated counterpart. Bioconjugation steps are extremely crucial. Practical implications: These QDs could be utilized for highly effective biolabelling and bioimaging in-vivo as well as in-vitro applications. Originality/value: The synthesis has been majorly modified, and the bioconjugation has been prepared in a novel method. There is limited reported work with this much description of the differences in conjugated and unconjugated QDs.

7

Organiczne diody elektroluminescencyjne na bazie pochodnych pirazolochinoksalin

Pokladko-Kowar Monika, Wojtasik Katarzyna

Przegląd Elektrotechniczny

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2022

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R. 98, nr 9

220--223

PL

Pochodne pirazolochinoksalin (A-PQX) badano pod kątem zastosowań w organicznych diodach elektroluminescencyjnych (OLED). Wykonane zostały pomiary widm absorpcyjnych, fotoluminescencyjnych oraz elektroluminescencyjnych. Zbudowane zostały jednowarstwowe komórki o strukturze ITO/PEDOT:PSS/PVK+A-PQX/Ca/Al. Wyznaczone zostały parametry charakterystyczne dla OLED. Maksymalna luminescencja otrzymana dla tych struktur wynosiła 884 cd/m2 dla diody na bazie 7-N,N-dietylo-1-fenylo-3-metylo-1H-pirazolo[3,4-b]chinoksaliny (7- PQX).

EN

Pyrazoloquinoxaline derivatives (A-PQX) have been studied for applications in organic light emitting diodes (OLEDs). Single-layer OLEDs with the structure: ITO/PEDOT:PSS/PVK+A-PQX/Ca/Al were built. Parameters characteristic for OLED were determined. The absorption, photoluminescent and electroluminescent spectra were measured. The maximum luminescence obtained for these structures was 884 cd/m2 for a diode based on 7-N,N-diethyl-3-methyl-1-phenyl-1H-pyrazolo[3,4-b]quinoxaline (7A-PQX).

8

Światłoczułe barwniki organiczne o właściwościach luminescencyjnych – teoria i zastosowanie

Duda Alicja, Kopyciński Bartosz

Ochrona przed Korozją

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2022

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nr 1

12--19

PL

Zjawisko fotoluminescencji obejmuje fluorescencję i fosforescencję, które od blisko 180 lat stanowią przedmiot licznych badań i obserwacji naukowych. Jedną z grup związków chemicznych wykazujących zdolność do emisji kwantów światła na drodze wzbudzenia promieniowaniem elektromagnetycznym są barwniki organiczne. Posiadające unikalne właściwości fizykochemiczne, znajdują one zastosowanie w wielu dziedzinach nauki i przemysłu, takich jak elektronika, włókiennictwo czy branża medyczna. Niniejszy przegląd obejmuje opis fizycznych podstaw zjawisk fotoluminescencji wraz z omówieniem budowy i zastosowania wybranych grup organicznych substancji barwiących zaliczanych do fotoluminoforów.

EN

Photoluminescence phenomenon can be divided into fluorescence and phosphorescence which are a subject of research for almost 180 years now. Organic dyes are one of the groups of chemicals which can show the ability to emission of a light quanta as a result of excitation with electromagnetic radiation. Having unique physicochemical properties they can be applied in many industry branches such as electronics, textiles or medicinal technologies. This review focuses on a description of the physical foundations of the photoluminescence phenomenon as well as the structure and applications of selected organic compounds classified as photoluminophores.

9

Signal processing for time resolved photoluminescence spectroscopy

Grodecki Kacper, Murawski Krzysztof, Rutkowski Jarosław, Kowalewski Andrzej, Sobieski Jan

Opto-Electronics Review

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2021

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Vol. 29, No. 3

91--96

EN

Accurate determination of material parameters, such as carrier lifetimes and defect activation energy, is a significant problem in the technology of infrared detectors. Among many different techniques, using the time resolved photoluminescence spectroscopy allows to determine the narrow energy gap materials, as well as their time dynamics. In this technique, it is possible to observe time dynamics of all processes in the measured sample as in a streak camera. In this article, the signal processing for the above technique for Hg1-xCdxTe with a composition x of about 0.3 which plays an extremely important role in the mid-infrared is presented. Machine learning algorithms based on the independent components analysis were used to determine components of the analyzed data series. Two different filtering techniques were investigated. In the article, it is shown how to reduce noise using the independent components analysis and what are the advantages, as well as disadvantages, of selected methods of the independent components analysis filtering. The proposed method might allow to distinguish, based on the analysis of photoluminescence spectra, the location of typical defect levels in HgCdTe described in the literature.

10

Peculiarities in optical response of hybrid-barrier GaSb/InAs/AlSb resonant tunneling diode structure

Dyksik M., Motyka M., Rygała M., Pfenning A., Hartmann F., Weih R., Worschech L., Höfling S., Sęk G.

Optica Applicata

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2021

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Vol. 51, nr 2

171--180

EN

We present comprehensive investigation of the optical properties of hybrid-barrier GaSb-based resonant tunneling structures, containing a bulk-like GaInAsSb absorption layer and two asymmetric type II GaSb/InAs/AlSb quantum wells. Methods of optical spectroscopy by means of Fourier-transformed photoluminescence and photoreflectance are employed to probe optical transitions in this complex multilayer system. Based on the comparison between the absorption-like and emission-like spectra (also in function of temperature) confronted with band structure calculations four main transitions could be resolved and identified. For one of them, there has been observed unusually strong linear polarization dependence never reported in structures of that kind. It has been interpreted as related to a transition at the GaSb/GaInAsSb interface, for which various scenarios causing the polarization selectivity are discussed.

11

Structural, morphological and photoluminescent properties of annealed ZnO thin layers obtained by the rapid sol-gel spin-coating method

Sypniewska Małgorzata, Szczesny Robert, Popielarski Paweł, Strzałkowski Karol, Derkowska-Zielinska Beata

Opto-Electronics Review

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2020

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Vol. 28, No. 4

182--190

EN

ZnO thin layers were deposited on p-type silicon substrates by the sol-gel spin-coating method and, then, annealed at various temperatures in the range of 573-873 K. Photoluminescence was carried out in the temperature range of 20-300 K. All samples showed two dominant peaks that have UV emissions from 300 nm to 400 nm and visible emissions from 400 nm to 800 nm. Influence of temperature on morphology and chemical composition of fabricated thin layers was examined by XRD, SEM, FTIR, and Raman spectroscopy. These measurements indicate that ZnO structure is obtained for samples annealed at temperatures above 573 K. It means that below this temperature, the obtained thin films are not pure zinc oxide. Thus, annealing temperature significantly affected crystallinity of the thin films.

12

The influence of quantum well and barrier thicknesses on photoluminescence spectra of InGaAs/AlInAs superlattices grown by LP-MOVPE

Łozińska Adriana, Badura Mikołaj, Bielak Katarzyna, Ściana Beata, Tłaczała Marek

Optica Applicata

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2020

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Vol. 50, nr 2

251--256

EN

In the presented work, the influence of the quantum well and barrier thicknesses on optical characteristics of InGaAs/AlInAs superlattices was reported. Six different structures of In0.53Ga0.47As/Al0.48In0.52As superlattices lattice-matched to InP were grown by low pressure metal organic vapour phase epitaxy (LP-MOVPE). Optical properties of the obtained structures were examined by means of photoluminescence spectroscopy. This technique allows quick, simple and non-destructive measurements of radiative optical transitions in different semiconductor heterostructures.The analysis of recorded photoluminescence spectra revealed the influence of the quantum well and barrier thicknesses on the emission line energy.

13

Photoluminescence and Raman spectroscopies as an optical approach of stress determining in MOVPE grown quantum cascade laser structures

Łozińska Adriana, Badura Mikołaj, Jadczak Joanna, Bielak Katarzyna, Ściana Beata

Optica Applicata

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2020

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Vol. 50, nr 2

289--299

EN

In the presented work, an optical approach of stress determining in metalorganic vapor phase epitaxy (MOVPE) grown quantum cascade laser (QCL) structures was reported. In the case of such sophisticated structures containing hundreds of thin layers, it is important to minimize the stress generated in the QCL core. Techniques enabling determination of stress in such thin layers as those described in the article are photoluminescence and Raman spectroscopies. Based on Raman shift or changes in photoluminescence signal, it is possible to analyze stress occurring in the structure.

14

Study of Ho doped Ag2S thin films prepared by CBD method

Yadu Goverdhan, Pateria M. Akash, Deshmukh K.

Materials Science Poland

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2020

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Vol. 38, No. 1

206--213

EN

Ho doped Ag2S thin films were grown on the glass substrate by chemical bath deposition (CBD) method at room temperature. The bath contained aqueous solution of silver nitrate, thiourea, EDTA, ammonia and holmium nitrate. Silver nitrate was used as a silver (Ag+) ion source; thiourea as sulfur (S−) ion source, EDTA was a complexing agent while ammonia was used to maintain pH, Ho(NO3)3 was taken as a source of Ho ions. The optical absorption edge of undoped (pure) and Ho doped silver sulfide films was determined between 324 nm and 298 nm showing blue shift as compared to bulk Ag2S. Band gaps calculated from Tauc plot also showed an increase in values for doped samples. The increase in band gap indicates reduced particle size in the prepared Ho doped films. The photoluminescence emission peaks were observed at around 578 nm to 601 nm wavelength and excitation peaks were found at 351 nm to 294 nm for undoped and doped films. The SEM micrograph consists of globular ball type and flower type structures observed in the prepared films of Ho doped Ag2S.

15

Growth, structural and optical properties of novel nonlinear optical potassium phthalate di lithium borate (KPDLiB) single crystals

Mohanraj K., Balasubramanian D., Jhansi N.

Materials Science Poland

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2020

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Vol. 38, No. 2

214--218

EN

Novel nonlinear optical semi-organic, potassium phthalate di lithium borate (KPDLiB) single crystals were successfully grown by the slow solvent evaporation technique. Good crystalline nature and an orthorhombic structure were confirmed by powder X-ray diffraction and single crystal X-ray diffraction studies. The functional groups of KPDLiB were identified using FT-IR spectrum recorded in the range of 4000 cm-1 to 450 cm-1. UV-Vis spectrum showed transmitting ability of the crystals in the entire visible region. The photoluminescence spectrum exhibited good fluorescence emission in a visible region at 384 nm, 416 nm and 578 nm. The second harmonic generation efficiency of the grown crystal was evaluated from Kurtz powder technique.

16

Spectroscopic properties of Er3+-doped fluorotellurite glasses modified by Nb2O5 and WO3

Burtan-Gwizdała Bożena, Reben Manuela, Cisowski Jan, El Sayed Yousef, Lisiecki Radosław, Grelowska Iwona

Optica Applicata

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2019

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Vol. 49, nr 3

393--402

EN

We have investigated the spectroscopic properties of Er3+-doped fluorotellurite glasses with the basic molar composition 75%TeO2–10%P2O5–10%ZnO–5%PbF2, modified by replacing 5% TeO2 by a metal oxide, namely WO3 or Nb2O5. The absorption edge of the glasses studied has been described within the Urbach approach, while the absorption and photoluminescence spectra have been analyzed in terms of the standard Judd–Ofelt theory, along with the photoluminescence decay of the 4I13/2 and 4S3/2 levels of the Er3+ ion. The absorption and emission spectra of the 4I15/2↔ 4I13/2infrared transition have been analyzed within the McCumber theory to yield the peak emission cross-section and figure of merit for the amplifier gain. It appears that the fluorotellurite glass containing WO3 as a modifier is characterized by the largest figure of merit, indicating this matrix as a promising new host for doping with Er3+ ions.

17

Nature of gas sensitivity of dyes on the base of Sn(IV) complexes

Doycho Igor K., Gevelyuk Sergiy A., Lepikh Jaroslav I., Rysiakiewicz-Pasek Ewa

Optica Applicata

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2019

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Vol. 49, nr 3

427--436

EN

Sensitivity of dyes on the base of 4-valence tin complexes to the composition of environment was researched. It has been found out that such dyes by themselves keep stability and inactivity to the composition of atmosphere. However, the photoluminescence properties of the nanostructures on their base can differ sufficiently depending on conditions of their formation. So the glow intensity of the nanoparticle ensembles of dyes having amine substitute in the hydrazonic fragment depends on the concentration of solution which was used during their formation. Optimal concentration exists and its excess leads to weak luminescence due to concentration quenching. Thus, if the nanoparticle ensemble, which was formed at the optimal concentration will be placed into ammonium atmosphere, it will be equivalent to formation of this ensemble by inflated concentration of the saturated solution. So photoluminescence of such system will be weak. Thereby reduced glow intensity will keep sufficiently long time due to the appearance of leakage channels in the form of bridge bonds. In such manner one can register the presence of ammonium in the environment. Initial intensity of luminescence may be re-established by removing extraneous gas with the aid of the short-time low-temperature anneal. In addition, the ligand in the coordination set of the dye plays a part of an interstitial impurity, so its presence leads to certain distribution of the charges in the system. It has been estimated experimentally that less intensive glow corresponds to the charge distribution in the system with the one-dentant ligand, namely by higher content of chlorine ions than in the case of bi-dentant one. This difference is more evident for dyes having hydroxyl substitute in the hydrazonic fragment. Thus, if the nanoparticle ensemble of such dye having a bi-dentant ligand will be placed into the atmosphere containing hydrogen chloride vapours, it changes the charge distribution to the typical one for the dye having one-dentant ligand artificially. It also will lead to weakening of the glow of the system. Initial intensity of luminescence may be re-established by removing the extraneous gas again with the aid of the anneal by the same conditions. The usage of specified properties makes it possible to construct reliable and responsive detectors of ammonium or hydrogen chloride vapours by the change of the detecting element in the known luminescence gas sensors to the nanoparticle ensemble of an appropriate dye.

18

Structural and optical properties of Dy3+ doped Sr2SiO4 phosphors

Verma Durga, Patel R. P., Verma Mohan L.

Materials Science Poland

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2019

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Vol. 37, No. 1

55--64

EN

Dysprosium doped strontium silicate phosphor namely (Sr2SiO4:Dy3+) was prepared by low-temperature solution combustion method using urea (CO(NH2)2) as a fuel. The material was characterized by powder X-ray diffraction (XRD), FT-IR, SEM and EDX. The average crystallite sizes was calculated by Scherer formula. Thermoluminescence study was carried out for the phosphor which showed single glow curve. The kinetic parameter were calculated by using Chen’s glow curve method. Photoluminescence spectra revealed strong transition at 473 nm (blue), 571 nm (yellow) and weak transition at 645 nm (red). These peaks were assigned to transition 4F9/2 → 6H15/2, 13/2 , 11/2. CIE graph of Sr2SiO4:Dy3+phosphor is suitable for the generation of white light emission.

19

Investigation of the structural, optical and photoluminescence properties of electrosynthesized hexagonal nanocrystalline Cd0.3Zn0.7S thin film

Dhaygude H. D., Fulari V. J.

Materials Science Poland

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2019

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Vol. 37, No. 3

300--303

EN

In this paper, Cd0.3Zn0.7S thin film has been electrodeposited from aqueous bath containing CdSO4, ZnSO4, Na2S2O3 and EDTA, having pH ~ 14. The structural, optical, morphological, surface wettability and photoluminescence properties of the film were investigated. The XRD pattern showed that the film consisted of mixed phases of CdS and ZnS with polycrystalline structure. The bandgap of the film was evaluated as 2.69 eV. The AFM study revealed that the Cd0.3Zn0.7S thin film contained spherical grains with root mean square roughness of 6.09 nm. The water contact angle measurement showed that the thin film was hydrophilic in nature. Moreover, the PL study revealed that the excitation wavelength was 460 nm.

20

Effect of Sm concentration on optical and electrical properties of CdSe nanocrystalline thin film

Pathak K. K., Pateria Mimi Akash, Deshmukh Kusumanjali, Jha Piyush

Materials Science Poland

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2019

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Vol. 37, No. 1

33--38

EN

Present paper reports optical and electrical properties of samarium doped CdSe nanocrystalline thin film which was grown on a glass substrate by chemical bath deposition method (CBD). X-ray diffraction (XRD) analysis revealed that the deposited films were nanocrystalline with sphalerite cubic structure. The average crystallite size calculated from FWHM of XRD peaks was found to be 10.11 nm. The bandgap of the Sm doped CdSe nanocrystalline thin films was calculated to be 1.91 eV to 2.22 eV. The optical absorption edge of undoped (pure) and Sm doped CdSe films was obtained between 650 nm to 640 nm showing blue shift as compared to bulk CdSe. Sm doping further enhanced the photoconductivity of these films. The I-V characteristic confirmed the suitability of prepared films for photosensor applications.