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A Comparative Study of Single layer InAs SK, sml, and Coupled SK-on-sml QDs Heterostructure by incorporating InGaAsSb (Type-II) as Capping Layer 30

A Comparative Study of Single layer InAs SK, SML, and Couple...

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Conference on Physics and Simulation of Optoelectronic Devices XXX at SPIE OPTO Conference

作者： Choudhary, Samishta Kumar, Ravindra Mantri, Manas Ranjan Dutta, Anindya Chakrabarti, Subhananda Indian Inst Technol Ctr Res Nanotechnol & Sci Mumbai Maharashtra India Indian Inst Technol Dept Elect Engn Mumbai Maharashtra India Indian Inst Technol Dept Chem Mumbai Maharashtra India

ISBN: (纸本)9781510648623;9781510648616

In this study, variation in Sb composition in In0.18Ga0.82AsYSb1-Y as capping layer (CL) over SK QDs and matrix material (MM) in 6 stacks of sml QDs for InAs sml, and strain coupled InAs SK-on-sml QDs heterostructure have been done theoretically. The structural and optical properties have been investigated through Nextnano++ software. Different single-layer SK (A-series), sml (B-series), and coupled SK-on-sml QDs (C- series) structures have been modeled for this study. Two main strain components, hydrostatic and biaxial strain have been computed simultaneously with the solution of 3-D Schrodinger's equation. The hydrostatic strain is compressive in the growth direction and gives information about carrier confinement in the conduction band while a biaxial strain is tensile in the growth direction and gives information about splitting in the valance band. There is a significant improvement of hydrostatic and biaxial strain observed for A-series and B-series structures respectively, which have quaternary capping, which helps in reduced overall strain and reduced InAs QDs desorption. In Addition to that, the coupled SK-on-sml structures (C-series) with InGaAsSb (Sb-15 and 25%) as capping layer and matrix layer possess more biaxial strain and reduced hydrostatic strain as compared to the conventional coupled structures with InGaAs as matrix material of sml and GaAs as capping layer over SK. The computed PL emission wavelength for proposed C-series structures offers a red-shift over conventional coupled structures. These configurations show type-II band alignment which can be used for various optoelectronic applications in the SWIR regime such as solar cells, long-range communication, etc. This study can be advantageous for the optimization of strain-coupled heterostructures.

关键词： Quantum dots SK sml SK-sml InGaAsSb Strain Wavelength and Eigen states

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Enhancing the Quantum Confinement Effect by means of Quaternary Al_xGa_yIn_1-x-yAs Barrier Material in type - I InAs/In_xGa_1-xAs sml QDs for Laser Applications

Enhancing the Quantum Confinement Effect by means of Quatern...

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Conference on High Power Lasers and Applications

作者： Shriram, Saranya Reddy Chakrabarti, Subhananda Indian Inst Technol Dept Elect Engn Mumbai 400076 Maharashtra India

ISBN: (纸本)9781510643895

The smaller lattice constant and high band gap quaternary - capped AlxInyGa1-x-yAs material acts as a confinement - enhancing (CE) barrier layer in type - I InAs/InxGa1-x As sub-monolayer (sml) quantum dot (QD) optoelectronic devices. The QDs grown inside In0.15Ga0.85As matrix surrounded by AlxGayIn1-x-yAs/GaAs barriers, resembles of dot -in - a - well (DWELL) heterostructure to achieve higher device performance. A larger in - plane compressive strain gets induced due to smaller lattice constant of CE barrier layer and this effect can be probed for designing higher modal gain and low - threshold current density vertical cavity surface - emitting lasers (VCSELs). The decreasing In content in CE layers increases the compressive strain in QDs, leading to reduced threshold current by decreasing (increasing) the background carrier concentration (conduction band, CB offset). The increased CB offset with Al (0.21), In (0.21) contents will therefore prevent the carriers from escaping to quantum well (QW) or barrier layers, thus non - radiative leakage current effects can be reduced. We have analyzed the primary strain tensors: hydrostatic and biaxial strain, photoluminescence (PL) emission energies using Nextnano++ simulations based on 8 - band k.p theory. Both the hydrostatic and biaxial strain increases inside QD, capping layers for increasing In (Al) composition, facilitating the threshold current reduction. Through the strain analysis, the material gain to carrier characteristics can be figured out for the efficient design of VCSELs. The QD low (19 K) and room -temperature (300 K) PL eigen energies were found at 1.1805 (1.1759) eV and 1.111 (1.177) eV for Al0.2Ga0.8As/GaAs and Al0.21Ga0.58In0.21As/GaAs CE layers.

关键词： sml VCSELs threshold current compressive strain CB offset nextnano plus

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Safety assessment of the process sml Maschinengesellschaft, based on sml technology, used to recycle post-consumer PET into food contact materials

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EFSA JOURNAL 2021年第8期19卷 e06795页

作者： Lambre, Claude Baviera, Jose Manuel Barat Bolognesi, Claudia Chesson, Andrew Cocconcelli, Pier Sandro Crebelli, Riccardo Gott, David Michael Grob, Konrad Mengelers, Marcel Mortensen, Alicja Riviere, Gilles Steffensen, Inger-Lise Tlustos, Christina Van Loveren, Henk Vernis, Laurence Zorn, Holger Dudler, Vincent Milana, Maria Rosaria Papaspyrides, Constantine Tavares Pocas, Maria de Fatima Lioupis, Alexandros Lampi, Evgenia

The EFSA Panel on Food Contact Materials, Enzymes and Processing Aids (CEP) assessed the safety of the recycling process sml Maschinengesellschaft (EU register number RECYC203), which uses the sml technology. The input is hot caustic washed and dried poly(ethylene terephthalate) (PET) flakes mainly originating from collected post-consumer PET containers, with no more than 5% PET from non-food consumer applications. The flakes are heated in an infrared (IR) dryer, then dried with hot air and extruded with vacuum degassing to sheets or pellets. Having examined the challenge test provided, the Panel concluded that the infrared drying (step 2), air drying (step 3) and extrusion (step 4) are critical in determining the decontamination efficiency of the process. The operating parameters to control the performance of these critical steps are temperature and residence time for all steps, air flow rate for step 3 and pressure for step 4. The Panel concluded that this recycling process is able to ensure that the level of migration of potential unknown contaminants into food is below the conservatively modelled migration of (a) 0.1 mu g/kg food, exposure scenario for infants, when such recycled PET is used at up to 50% in mixture with virgin PET and of (b) 0.15 mu g/kg food, exposure scenario for toddlers, for contact with all types of foodstuffs except for packaged water at up to 80%, for long-term storage at room temperature, with or without hotfill, and at up to 100% for storage under frozen and refrigerated conditions. Therefore, the Panel concluded that the recycled PET produced by this process is not of safety concern when used under the evaluated conditions. The final articles made of this recycled PET are not intended to be used in microwave and conventional ovens and such uses are not covered by this evaluation. (C) 2021 European Food Safety Authority. EFSA Journal published by John Wiley and Sons Ltd on behalf of European Food Safety Authority.

关键词： sml sml Maschinengesellschaft mbH food contact materials plastic poly(ethylene terephthalate) (PET) recycling process safety assessment

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Investigations on heterogeneously coupled Submonolayer (sml) on Stranski-Krastanov (SK) Quantum Dot heterostructures with higher (0.1 ML/sec) and lower (0.05 ML/sec) growth rates 17

Investigations on heterogeneously coupled Submonolayer (SML)...

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Conference on Quantum Dots, Nanostructures, and Quantum Materials - Growth, Characterization, and Modeling XVII

作者： Samesta Saha, Jhuma Panda, Debiprasad Das, Debabrata Dongre, Suryansh Chakrabarti, Subhananda Indian Inst Technol Ctr Res Nanotechnol & Sci Mumbai 400076 Maharashtra India Indian Inst Technol Dept Elect Engn Mumbai 400076 Maharashtra India

ISBN: (纸本)9781510633469

We are studying here the heterogeneously coupled Submonolayer (sml) on Stranski-Krastanov (SK) quantum dot (QD) heterostructures. The consolidation in sml on SK heterostructure has been observed by varying growth rate as 0.05 and 0.1 ML/sec. The barrier thickness between SK and sml QDs has also been varied as 5, 7.5, and 10 nm. Pphotoluminescence(PL) study shows transition of carriers with dot size distribution. The peak from SK QDs is prominent in PL spectra of both growth rate samples. The absence of sml peak from the PL might be due to the tunnelling of carriers from sml to SK QDs, which follows the SK ground energy states for recombination. sml peak is visible only in low growth rate sample for barrier thickness of 10 nm, as with higher barrier thickness there is reduction in the probability of tunnelling of carriers. Samples with lower growth rate shows bimodal dot size distribution at barrier thickness 7.5nm, whereas higher growth rate samples shows monomodal dot size distribution. Compressive strains were extracted from high-resolution X-Ray diffraction (HRXRD) measurement. From the HRXRD measurement, it has been found that the strain decreases with increasing barrier thickness. Low growth rate samples have less strain as compared to high growth rate samples. In the lower growth rate samples, PL peak is red shifted as compared to higher growth rate samples due to less strain in the heterostructures and larger size QDs. Therefore, this study will be useful for advanced optoelectronic applications.

关键词： Quantum Dots SK sml X-Ray Diffraction Photoluminescence

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A comparative analysis between heterogeneously coupled Stranski-Krastanov (SK) on Submonolayer (sml) and Submonolayer (sml) on Stranski- Krastanov (SK) Quantum Dot heterostructures 17

A comparative analysis between heterogeneously coupled Stran...

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Conference on Quantum Dots, Nanostructures, and Quantum Materials - Growth, Characterization, and Modeling XVII

作者： Samesta Saha, Jhuma Panda, Debiprasad Das, Debabrata Chakrabarti, Subhananda Indian Inst Technol Ctr Res Nanotechnol & Sci Mumbai 400076 Maharashtra India Indian Inst Technol Dept Elect Engn Mumbai 400076 Maharashtra India

ISBN: (纸本)9781510633469

Heterogeneously coupled SK-smlQuantum Dot (QD) heterostructures has superior characteristics compared to homogeneously coupled SK QDs in terms of dot density, cumulative strain and absorption efficiency. Here, we have carried out a comparative analysis between heterogeneously coupled SK on sml and sml on SK QDs heterostructures. The barrier thickness between SK and sml QDs,in both structures, has been varied as 5, 7.5 and 10 *** tunnelling of carriers from one type of QD (SK/sml) to another type of QD (sml/SK)has been explicated through photoluminescence (PL) study. The appearance of sml peak along with the SK peak for higher barrier thickness has been observed in case of SK on sml QD heterostructure. This might be due to decrease in tunnelling probability of carriers and thereby, transition takes place from both SK and sml QDs. However, this phenomenon has not been observed in sml on SK QD heterostructures. The reason might be the reduced average barrier thickness between sml and SK QDs, which allowed tunnelling of all the carriers. Thus, sml peak was absent in all three sml on SK QD heterostructures. Moreover, strain distribution in all the heterostructures have been investigated through high resolution X-ray diffraction (HRXRD) measurements. The significant modification in structural morphology of QDs, can be obtained fromHRXRD, clearly demonstrates variation in strain with respect to barrier thickness. This comparative analysis would help the research community to choose the optimized heterostructure for desired optoelectronic applications.

关键词： SK sml PL Coupled QD Strain Barrier thickness

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Effect of ex-situ annealing on coupled hybrid InAs Stranski-Krastanov (SK) on Submonolayer (sml) Quantum Dot heterostructures with different spacer layer thickness

Effect of ex-situ annealing on coupled hybrid InAs Stranski-...

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Conference on Low-Dimensional Materials and Devices

ISBN: (纸本)9781510637375

The strain-coupled InAs Stranski-Krastanov (SK) and submonolayer (sml) quantum dot (QD) heterostructure improves the optoelectronic properties of the infrared photodetector as compared to the single SK or sml heterostructures. The discussed heterostructures for SK on sml are grown with three different spacer layer thicknesses (5, 7.5 and 10 nm) between SK and sml dots and each sample is grown with two different growth rates (0.1 ML/sec and 0.05 ML/sec). In this study, we are modulating the optical and structural properties of the heterogeneously coupled SK on sml structure with ex-situ annealing treatment. Rapid thermal annealing at 650 degrees C and 700 degrees C is done for all samples. Photoluminescence (PL) result shows blue shift in the peak position for annealed samples compared to the as-grown samples. The reason for this blue shift can be (1) In out-diffusion from the dots, or (2) Diminution in dot size. A reduction in full width half maxima (FWHM) of the PL spectra along with the annealing temperature is observed, which confirms the smaller size of dots after annealing. Additionally, substantial variation in strain profile for these hybrid structures has been discerned by high resolution X-ray diffraction (HRXRD). Hence, this study would definitely help to optimize the ex-situ annealing temperature on heterogeneously coupled SK-sml structure for wavelength tunable photodetection in the near infrared regime.

关键词： SK sml Photoluminescence Coupled QD Strain Barrier thickness

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Auto-Focus algorithm based on improved sml evaluation function

Auto-Focus algorithm based on improved SML evaluation functi...

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Annual Conference of the Chinese-Society-of-Optical-Engineering (CSOE) on Optical Sensing and Imaging Technology (AOPC)

作者： Ma Xiaoyu Li Qiaoling Chinese Acad Sci Xian Inst Opt & Precis Mech Xian 710119 Peoples R China Univ Chinese Acad Sci Beijing 100049 Peoples R China

ISBN: (数字)9781510634497

ISBN: (纸本)9781510634497

The traditional spatial domain sharpness evaluation functions usually have a larger amount of calculation, and the calculation time is relatively longer. Besides, its anti-noise ability is weak, and it is easy to be disturbed by the background factors in the image. The above problems will have an impact on the real-time, sensitivity and reliability of the auto-focus system. In order to overcome these shortcomings, an improved sml sharpness evaluation function combined with threshold is proposed in this paper. This algorithm improve the sml function firstly, and make full use of the edge information of the image. Then a threshold is introduced to distinguish the edge points from non-edge points. So it can not only highlight the edge information while restraining the noise and the flat area in the background of the image, but also can reduce the calculation amount of the evaluation function and improve the real-time performance of the auto-focusing system. Finally verifies the effect of the improved evaluation function based on the simulation experiments. The results show that the algorithm proposed in this paper has better sensitivity and anti-noise ability, and can evaluate the sharpness of defocused images accurately and steadily.

关键词： auto-focus sharpness evaluation function threshold gradient sml image processing

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sml在香港设立首个无线射频识别技术创新及研发中心

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传感器世界 2022年第5期28卷 43-43页

2022年5月11日,数字化方案服务商sml集团宣布在中国香港启动首个无线射频识别技术(RFID)创新及研发中心。该中心将有助于sml拓展其全球业务版图,与品牌商携手发展可持续未来。sml集团首席运作总监陈家驹先生表示:“RFID创新及研发中心... 详细信息

2022年5月11日,数字化方案服务商sml集团宣布在中国香港启动首个无线射频识别技术(RFID)创新及研发中心。该中心将有助于sml拓展其全球业务版图,与品牌商携手发展可持续未来。sml集团首席运作总监陈家驹先生表示:“RFID创新及研发中心将加快sml策略性地扩展业务至各行业,未来每件物品都将带有数字化标签,我们有信心见证该中心在相关领域获得蓬勃发展,sml也将致力于以高效生产出符合各行业最高标准的RFID标签。”

关键词： RFID标签品牌商 sml 中国香港扩展业务研发中心数字化服务商

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sml集团RFID科技及企业传讯高级副总裁孙苑琳——sml:以RFID技术传递新价值

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中国自动识别技术 2019年第6期 33-35页

作者：郑昱不详

sml集团于1985年成立,至今已有约35年发展历史。截至目前,sml集团是全球第二大传统标签以及RFID标签供应商,足迹遍布30多个国家。目前,在所有已部署RFID库存管理软件的欧美零售门店中,sml的占有率达到30%。前不久,sml集团在上海设立了... 详细信息

sml集团于1985年成立,至今已有约35年发展历史。截至目前,sml集团是全球第二大传统标签以及RFID标签供应商,足迹遍布30多个国家。目前,在所有已部署RFID库存管理软件的欧美零售门店中,sml的占有率达到30%。前不久,sml集团在上海设立了全球第二家零售思维空间(Retail Ideation Space,以下简称“零维空间”)。旨在帮助零售企业了解一站式RFID技术在零售供应链的应用和其所能带来的潜在价值。

关键词： RFID技术 RFID标签一站式库存管理副总裁零售企业 sml 潜在价值

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Temporal dynamics of transparent exopolymer particles in surface waters and sea surface microlayer in the coastal Eastern Mediterranean Sea

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REGIONAL STUDIES IN MARINE SCIENCE 2025年 85卷

作者： Tzempelikou, Eleni Zeri, Christina Pitta, Elli Assimakopoulou, Georgia Pavlidou, Alexandra Rousselaki, Eleni Hellen Ctr Marine Res HCMR Inst Oceanog Anavyssos 19013 Greece

The aim of this study is to investigate the dynamics of transparent exopolymer particles (TEPs) in relation to phytoplankton, dissolved/total organic carbon (DOC-TOC), dissolved monosaccharides (MCHOs), dissolved polysaccharides (PCHOs), in surface waters including the sea surface microlayer (sml), during an annual cycle at a coastal site in the Eastern Mediterranean Sea. TEPs in the sml ranged from 238 to 1094 mu g Xeq L-1 and in the ULW from 112 to 674 mu g Xeq L-1. Mean sml enrichment factors (EFs) compared to underlying water (ULW) were found equal to 1.7 +/- 0.8, 3.4 +/- 2.0, 4.2 +/- 2.9 and 3.5 +/- 2.7 for TEPs, DOC, MCHOs and PCHOs, respectively, indicating a variable sml enrichment. TEPs did not show any correlation with Chlorophyll a (Chla) and were maintained in surface waters for a long period presenting a significant positive relationship to water temperature (T). The carbon content of TEPs (TEP-C) corresponded to similar to 7 % of TOC in the sml and to similar to 20 % in the ULW. Although, the annual variability of TEPs followed similar patterns in the two layers, correlation analysis and Principal component analysis (PCA) indicate that different processes take place between the sml and ULW. In the ULW, TEPs increase in parallel to MCHOs and in the expense of PCHOs. In the sml, TEPs and Dissolved Carbohydrates (CHOs) do not correlate while a strong positive correlation is established between the two CHO fractions. These differences show the decoupling of TEPs precursor material between the two layers in coastal waters of the Saronikos Gulf and suggest that different processes take place in the two layers.

关键词： sml TEP Monosaccharides Polysaccharides Dissolved organic matter Saronikos Gulf

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