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Solar cell performance enhancement using nanostructures

MATERIALS SCIENCE AND engineering B-ADvANCED FUNCTIONAL SOLID-STATE MATERIALS 2024年 307卷

作者： Tumram, Priya v. Nafdey, Renuka Kautkar, Pranay R. Agnihotri, S. v. Khaparde, Rohini A. Wankhede, S. P. Moharil, S. v. Amolakchand Mahavidyalaya Dept Phys Yavatmal 445001 India Shri Ramdeobaba Coll Engn & Management Nagpur 440013 India JMT Arts & JJP Sci Coll VMV Commerce Nagpur 440008 India KDK Coll Engn Dept Phys Nagpur 440009 India Rashtrasant Tukadoji Maharaj Nagpur Univ Dept Phys Nagpur 440033 India

The review focuses on the recent developments in nanostructure based solar cell technology. Apart from successfully commercialized crystalline silicon (c-Si) solar cells, various other solar cells have been a topic of research since last few decades because limitations of c-Si solar cells such as cost and low efficiency. Though theoretically predicted solar cells efficiencies by Shockley and Queisser for various solar cells are high, real-world solar cell efficiencies are low due to various factors like spectral mismatch, reflection losses, recombination losses, incomplete absorption, etc. The efforts to enhance solar cell performance by using nanotechnology has facilitated development of altogether new types of devices such as quantum dot and nanowire solar cells. Quantum dot solar cells (QDSC) make use of Quantum dots for absorption of incident solar radiation. optical properties of the quantum dots can be manipulated through adjustment of the bandgap which depends on the size. The bandgap tuning makes QDSC adequate for multi-junction solar cells. QD of numerous semiconductors have been investigated for improving solar cell efficiency by exploiting various regions of the solar spectrum. Use of QDs for absorption of the solar light theoretical efficiency limit of mono-junction, as well as tandem cells can be improved. First principle calculations led to the prediction that the encasing QDs in the intrinsic region can significantly enhance the performance of p-i-n structures. The same logic can be used for the tandem cells as well. Apart from QDs, use of nanowires to attain similar improvement but through increasing the short-circuit current (Isc) has also been explored. On the other hand, the problem of optimizing the open-circuit voltage (voc) is not yet satisfactorily solved in photovoltaic devices based on nanowires. One of the approaches had been to incorporate nanophotonics in the design of a solar cell. This concept could be applied to almost all types of cel

关键词： Nanostructure Quantum dots Nanowires Solar cells Semiconductor

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Iterative and inverse design of a segmented reflector for uniform illumination on the road 22

Iterative and inverse design of a segmented reflector for un...

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Conference on current developments in lens design and optical engineering XXII

作者： Wu, Rubing Alisafaee, Hossein Rose Hulman Inst Technol Dept Phys & Opt Engn 5500 Wabash Ave Terre Haute IN 47803 USA

ISBN: (数字)9781510644670

ISBN: (纸本)9781510644670

We demonstrate an iterative and inverse design of a segmented reflector used to illuminate the road with a uniform light distribution and reduced glare to the oncoming traffic. design is set to meet the StvZO standard. The maximum brightness obtained is 1460 candela, which is five times brighter than a conventional headlamp of urban shared electric scooters and bicycles, resulting in improved visibility in dark environments. A prototype was built and tested at various environments. The tolerance analysis showed no negative influence on the desired standard light distribution. In addition to this iterative approach, a ray tracing code has been developed for inverse design and to map a desired uniform road illumination pattern back to the candela sensor for corresponding reflector design.

关键词： optical design Illumination Reflector design design for manufacturing Lucid-Shape

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Infrared Detector developments at Teledyne e2v for current and Future Missions

Infrared Detector Developments at Teledyne e2v for Current a...

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2022 International Conference on Space Optics, ICSO 2022

作者： Swindells, Ian Wheeler, Ross Jerram, Paul Kendall, Jeremey Read, Iain Teledyne e2v 106 Waterhouse Lane ChelmsfordCM1 2QU United Kingdom

ISBN: (纸本)9781510668034

There is increased interest in hyperspectral imaging space missions as a powerful remote sensing technique for Earth observation. The Teledyne HgCdTe FPA and digital ROIC technology enable Teledyne e2v to provide wide bandwidth, high frame-rate detector solutions that are enabling a simplification in hyperspectral instrument design for both institutional large scale missions and for future commercial constellations. In parallel Teledyne e2v are developing III-v technology for surveillance applications that could find use in future generations of space based instruments. © 2023 SPIE. All rights reserved.

关键词： Cadmium alloys

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Thermally reconfigurable varifocal silicon metalens 22

Thermally reconfigurable varifocal silicon metalens

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Conference on current developments in lens design and optical engineering XXII

作者： Archetti, Anna Lin, Ren-Jie Tsoulos, Ted, v Kiani, Fatemeh Restori, Nathanael Tagliabue, Giulia Ecole Polytech Fed Lausanne STI Lab Nanosci Energy Technol LNET CH-1015 Lausanne Switzerland Univ Padua Dept Biomed Sci Neurosci I-35131 Padua Italy

ISBN: (数字)9781510644670

ISBN: (纸本)9781510644670

Active optical components are essential building blocks for a wide variety of applications such as optical communications, microscopy, and illumination systems. Reconfigurable metasurfaces, which consist of arrays of sub-wavelength meta-atoms, can be engineered to uniquely realize compact and multifunctional optical elements, enabling light-polarization dynamic-control as well as beam steering, focusing or zooming. varifocal metalenses, in particular, have attracted increasing interests. Yet, going beyond mechanical modulation schemes to realize ultra-thin devices with fast modulation remains challenging due to the complex phase and phase-delay profiles involved. Recently, thermooptical effects in dielectric nanostructures have emerged as a promising solution to tune their optical resonances, offering unexplored opportunities for ultra-thin reconfigurable metalenses, in particular silicon based ones. In this work, we report a proof-of-concept design of an ultrathin (300 nm thick) and thermo-optically reconfigurable silicon metalens operating in the visible regime (632 nm). Importantly, we demonstrate that, using thermo-optical effects, it is possible to achieve continuous modulation of the focal-length at a fixed wavelength. In particular, operating under right-circularly polarized light, our metalens exhibits a linear focal shift from 165 mu m at 20 degrees C to 135 mu m at 260 degrees C, exceeding the lens focal depth. The average conversion efficiency of the lens is 26%, close to mechanically modulated devices, while its Strehl ratio is 0.99, confirming a diffraction-limited performance. Concurrently, in this work we report an automatized methodology to design a reconfigurable metalens, compute its layout and verify the expected performance. Overall, we envision that, by further optimization of the optical response of individual meta-atoms with machine-learning algorithms, thermally-reconfigurable silicon metalenses will emerge as a viable, chip-compatible soluti

关键词： Metasurface tunable lens varifocal metalens thermo-optic effect silicon nanofin resonator Pancharatnman-Berry geometric effect

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Metalens wide-angle receiver for free space optical communications 22

Metalens wide-angle receiver for free space optical communic...

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Conference on current developments in lens design and optical engineering XXII

作者： Islam, Md Shafiqul Zaman, Imam Uz Sadri-Moshkenani, Parinaz Khan, Mohammad Wahiduzzaman Boyraz, Ozdal Univ Calif Irvine Irvine CA 92717 USA

ISBN: (数字)9781510644670

ISBN: (纸本)9781510644670

Receiver field of regard is one of the major problems for free space optical (FSO) communications. Drift or vibrations in transceiver orientations reduces effective communication time. The methods implemented to overcome this limitation, often require bulky optical and complex mechanical assemblies with feedback control, that are not suitable for long run operation in an airborne system. In this paper, we propose a novel receiver system that can effectively reduce the impact of pointing errors. The system is composed of two metalenses and one off-the-shelf conventional lens. The first metalens focuses optical beam incident at different angles on the aperture, at different locations on focal plane. The second metalens is placed on the focal plane of first metalens. After passing through the second metalens, the beams become parallel to optical axis of the receiver optical system. The parallel beams are collected by a suitable off-the-shelf aspheric lens and focused back on single detector that sits on a point on the optical axis. The system is designed and analyzed by physical optics theory. With 0.5 mm receiver aperture and 50 mm diameter aspheric lens, Zemax simulation shows that the system can collect +/-5-degree incident angle with detector diameter of 273 mu m. COMSOL frequency domain simulation with smaller diameter beam shows that the efficiency of the 2 metalens system is about 80%. Efficient metalens design and beam compression at detector plane are two key features of the proposed system. The system relaxes the strict requirement of aligning the transmitter and receiver unit in FSO communication.

关键词： Metalens free space optical communication wide angle receiver

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design of Ultrashort Throw lenses with Catadioptric Relays for Curved Screens 22

Design of Ultrashort Throw Lenses with Catadioptric Relays f...

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Conference on current developments in lens design and optical engineering XXII

作者： Nishikawa, Jun Nishiyama, Mariko Sony Grp Corp R&D Ctr Atsugi TEC 4-14-1 Asahi Cho Atsugi Kanagawa 2430014 Japan

ISBN: (数字)9781510644670

ISBN: (纸本)9781510644670

An ultrashort throw lens with a catadioptric relay (USTCR) for curved screens has a half-field angle greater than 110 degrees. The angle of the principal ray incident on the aspherical mirror increases according to the height of the ray emitted from the object surface. A larger field angle leads to larger sag amount. Thus, the degree of difficulty in precision machining increases. In this study, we examined how the tangent of the concave mirror surface can be reduced such that it can be manufactured while maintaining the half-field angle and its optical performance. It was found that the interval between imaging points reaching the screen can be made constant by suppressing the change in the principal ray incident on the concave mirror by +1- 1 degrees or less, particularly in the area of a half-field angle of 90 degrees or more, and making the change in the tangent of the concave mirror surface constant. As an index of distortion, we show that the perimeter ratio (Pr) of the frame length, which was equally divided by 5 x5 in the screen, improved from 0.26 to 0.73. As one possible application, a projection system that can be realized with only 8 projectors is proposed, as opposed to conventional systems consisting of approximately 20 projectors in omni-directional projection systems.

关键词： ultrashort throw lens aspheric mirror sag amount concave mirror catadioptric relay lens lens design curved screen omni-directional projection system

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Towards a new generation long trace profiler LTP-2020: optical design of pencil beam interferometry sensor 10

Towards a new generation long trace profiler LTP-2020: Optic...

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Advances in Metrology for X-Ray and EUv Optics X 2023

作者： Takacs, P.Z. Lacey, Ian Yashchuk, valeriy v. Surface Metrology Solutions LLC MinneapolisMN55401 United States Lawrence Berkeley National Laboratory Advanced Light Source One Cyclotron Road BerkeleyCA94720 United States

ISBN: (纸本)9781510666047

Improvements in the quality of synchrotron beamline x-ray optics required for next-generation light sources (e.g. the ALS Upgrade project) drive the need to improve the performance of the metrology instrumentation used to measure these components. The Long Trace Profiler (LTP) that is in use at many synchrotron metrology laboratories around the world has some known issues that affect the accuracy of its measurements. The main error source is optical path difference (OPD) phase error introduced into the probe beam by inhomogeneities in the glass components used in the optical head. We have developed a new optical head design, LTP-2020, that replaces the cube polarizing beamsplitter (PBS) with a thin wedge plate polarizing beamsplitter (WPBS) and replaces the cemented doublet lens with an aspheric singlet. Both of these components significantly reduce the glass volume traversed by the laser probe beam. Careful attention to ghost ray interference produced by back reflection from optical surfaces is necessary to minimize distortion in the primary image that translates into systematic error in the slope angle measurement. We make extensive use of a commercial raytracing program to model the back reflections and adjust component parameters as necessary to minimize distortion. Deliberate misalignment of components is necessary to make the system perform correctly. Stringent requirements are placed on the 45◦ incidence coatings on the WPBS and on the normal incidence coatings on the lens and camera window elements. We encourage our colleagues who wish to upgrade their current LTP systems to join us in the procurement of these custom optical components. © 2023 SPIE.

关键词： optical design

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Large volumetric optical-resolution photoacoustic microscopy with image fusion based on CNN feature extraction 22

Large volumetric optical-resolution photoacoustic microscopy...

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Conference on current developments in lens design and optical engineering XXII

作者： Li, Sihang Wang, Zhuangzhuang Cao, Xiongjun Li, Zhihui Song, Xianlin Nanchang Univ Ji Luan Acad Nanchang 330031 Jiangxi Peoples R China Nanchang Univ Sch Informat Engn Nanchang 330031 Jiangxi Peoples R China

ISBN: (数字)9781510644670

ISBN: (纸本)9781510644670

Photoacoustic imaging(PAI) is a emerging powerful and efficient imaging technology. optical-resolution photoacoustic microscopy is an useful photoacoustic imaging technique combining the advantages of both optical imaging and acoustic imaging which obtains many attractive advanges such as high resolution, high contrast and so on. Laser beam is often focused strongly to achieve high resolution. However, this will lead to a poor depth-of-field and less structural information which limits the further application of this technology. A image fusion method based on CNN feature extraction is proposed to achieve large volumetric optical-resolution photoacoustic microscopy. First, two groups of simulated 3D photoacoustic data of different focal locations were obtained through photoacoustic microscopic imaging platform. Then B-scan data were fused and maximum projection of the reconstructed 3D data is taken to display the photoacoustic information. By comparing the source images and the fused image, we show that the proposed method can be implemented to obtain large volumetric and high-resolution photoacoustic images.

关键词： photoacoustic microscopy depth expandsion image fusion convolutional neural network

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Recent developments in layered double hydroxide structures with their role in promoting photocatalytic hydrogen production: A comprehensive review

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INTERNATIONAL JOURNAL OF ENERGY RESEARCH 2022年第3期46卷 2093-2140页

作者： Sherryna, Areen Tahir, Muhammad Univ Teknol Malaysia Dept Chem Engn Sch Chem & Energy Engn Johor Baharu 81310 Johor Malaysia UAE Univ Chem & Petr Engn Dept Al Ain U Arab Emirates

Layered double hydroxides (LDHs) have received scientific attractions due to their unique two-dimensional (2D) structure, band gap tunability, and compositional flexibility, leading to the facile incorporation of the metal species into their layered structure. The main objective of this review is to explore the current advancement of LDH-based photocatalysts for photocatalytic hydrogen production by focusing on the role of divalent and trivalent metal incorporations and their efficiency enhancement. Firstly, the mechanism of photocatalysis and its thermodynamics has been explicated to gain basic understanding and fundamentals. Secondly, a brief introduction to the overview of LDH photocatalysts with special attention to the effects of cationic incorporations on the optical properties and computational study towards the electronic density has been demonstrated. Besides, the thermal stability of LDH is briefly discussed, focusing on the effects of temperature towards the conversion into mixed-metal oxide (MMO). Next, the classification of LDH based on divalent and trivalent cationic elements and their role in the brucite layer of LDH are systematically discussed. Attention is given to the mechanistic properties of the extensively studied metals, such as Mg, Ni, Zn, Co, Cr, Fe, v and Al, with the efficiency enhancements through various engineering aspects are demonstrated. The overview summary on the efficient design of LDH is elucidated to provide a deep understanding for improving their photocatalytic properties. Lastly, the future perspectives and recommendations are discussed to provide new insight into the potential of LDH and render them a notable place in solar energy applications.

关键词： band engineering layered double hydroxide LDH heterojunction strategies metallic classification photocatalytic hydrogen production thermodynamics analysis

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current developments in lens design and optical engineering XX

Current Developments in Lens Design and Optical Engineering ...

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current developments in lens design and optical engineering XX 2019

ISBN: (纸本)9781510629011

The proceedings contain 29 papers. The topics discussed include: fundus camera versus smartphone camera attachment: image quality analysis;a water-polydimethylsiloxane liquid lens for variable focus experiments in an undergraduate laboratory;deconvolution process with GPU in a wavefront coding microscopy system;exposure of restore-L camera optical elements to a simulated orbital radiation environment;the design of a four-mirror anti-astigmatism astronomical telescope;introducing a dynamic deep neural network to infer lens design starting points;and application of GPUs in optical design software.

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