Solar Thermophotovoltaic Converters Based on Tungsten Emitters

2006 ◽  
Vol 129 (3) ◽  
pp. 298-303 ◽  
Author(s):  
V. M. Andreev ◽  
A. S. Vlasov ◽  
V. P. Khvostikov ◽  
O. A. Khvostikova ◽  
P. Y. Gazaryan ◽  
...  
Keyword(s):  
Band Gap ◽  
High Efficiency ◽  
Radiation Spectrum ◽  
Cost Effective ◽  
Fresnel Lens ◽  
Photocurrent Density ◽  
Back Side ◽  
High Concentration ◽  
Emitter System ◽  
Solar Powered

Results of a solar thermophotovoltaic (STPV) system study are reported. Modeling of the STPV module performance and the analysis of various parameters influencing the system are presented. The ways for the STPV system efficiency to increase and their magnitude are considered such as: improvement of the emitter radiation selectivity and application of selective filters for better matching the emitter radiation spectrum and cell photoresponse; application of the cells with a back side reflector for recycling the sub-band gap photons; and development of low-band gap tandem TPV cells for better utilization of the radiation spectrum. Sunlight concentrator and STPV modules were designed, fabricated, and tested under indoor and outdoor conditions. A cost-effective sunlight concentrator with Fresnel lens was developed as a primary concentrator and a secondary quartz meniscus lens ensured the high concentration ratio of ∼4000×, which is necessary for achieving the high efficiency of the concentrator–emitter system owing to trap escaping radiation. Several types of STPV modules have been developed and tested under concentrated sunlight. Photocurrent density of 4.5A∕cm2 was registered in a photoreceiver based on 1×1cm2GaSb cells under a solar powered tungsten emitter.

Packaging Issues and Solutions for Ultra-Low Power, High Efficiency GaN micro-LEDs for a Battery Free, Sub-mm2, Tetherless, Smart IoT System

2020 ◽  
Vol 2020 (1) ◽  
pp. 000181-000184
Author(s):  
F.R. Libsch ◽  
S.W. Bedell ◽  
B.C. Webb ◽  
A. Paidimarri
Keyword(s):  
Low Power ◽  
Flip Chip ◽  
High Efficiency ◽  
Low Voltage ◽  
Cost Effective ◽  
Back Side ◽  
Ultra Low Power ◽  
Emission Area ◽  
Sensor Platform ◽  
Side Emission

Abstract This paper discusses some design and implementation issues related to GaN micro-LED (μLED) incorporated into the heterogeneous packaging of IBM’s smart and secure sensor platform. For cost effective μLEDs, the sapphire substrate needs to be singulated reliably and with minimum kerf perimeter, be ultra-clean and smooth to allow back side emission without scattering, and high yielding front side flip chip bonding with 20μm C4s on 40μm pitch. The GaN μLEDs are design for low voltage/low power operation with an emission area of 20μm × 20μm with critical current density of ~10nA/μm2. Power and downlink data is delivered to the system via optical energy harvesting by on-silicon carrier photovoltaics and communication photodiode, respectively. Optical amplitude modulated uplink communication by heterogeneous packaging of the GaN μLED with a 14nm CMOS smart chip will be detailed and demonstrated in presentation.

scholarly journals High-Efficiency Photochemical Water Splitting of CdZnS/CdZnSe Nanostructures

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Chen-I Wang ◽  
Zusing Yang ◽  
Arun Prakash Periasamy ◽  
Huan-Tsung Chang
Keyword(s):  
Quantum Dots ◽  
Band Gap ◽  
Water Splitting ◽  
Chemical Bath Deposition ◽  
Conversion Efficiency ◽  
Light Absorption ◽  
High Efficiency ◽  
Saturated Calomel Electrode ◽  
Photocurrent Density ◽  
Solar Water Splitting

We have prepared and employed TiO2/CdZnS/CdZnSe electrodes for photochemical water splitting. The TiO2/CdZnS/CdZnSe electrodes consisting of sheet-like CdZnS/CdZnSe nanostructures (8–10 μm in length and 5–8 nm in width) were prepared through chemical bath deposition on TiO2 substrates. The TiO2/CdZnS/CdZnSe electrodes have light absorption over the wavelength 400–700 nm and a band gap of 1.87 eV. Upon one sun illumination of 100 mW cm−2, the TiO2/CdZnS/CdZnSe electrodes provide a significant photocurrent density of 9.7 mA cm−2 at −0.9 V versus a saturated calomel electrode (SCE). Incident photon-to-current conversion efficiency (IPCE) spectrum of the electrodes displays a maximum IPCE value of 80% at 500 nm. Moreover, the TiO2/CdZnS/CdZnSe electrodes prepared from three different batches provide a remarkable photon-to-hydrogen efficiency of 7.3 ± 0.1% (the rate of the photocatalytically produced H2 by water splitting is about 172.8 mmol·h−1·g−1), which is the most efficient quantum-dots-based photocatalysts used in solar water splitting.

CPV Modules Based on Lens Panels

2010 ◽  
Vol 74 ◽  
pp. 211-218 ◽  
Author(s):  
V.D. Rumyantsev ◽  
Yu.V. Ashcheulov ◽  
N.Yu. Davidyuk ◽  
E.A. Ionova ◽  
P.V. Pokrovskiy ◽  
...  
Keyword(s):  
Solar Cells ◽  
Heat Dissipation ◽  
Fresnel Lens ◽  
Test Method ◽  
Glass Sheet ◽  
Ir Absorption ◽  
Back Side ◽  
High Concentration ◽  
Small Aperture ◽  
Fresnel Lenses

A work on development of the high concentration photovoltaic (HCPV) modules with Fresnel lens panels and III-V multijunction cells is presented. A composite structure of the small-aperture area 40x40 (or 60x60) mm2 Fresnel lenses, united in a panel, was realized. A silicate glass sheet (front side of a module) serves as a superstrate for transparent microprisms formed in silicone. Small averaged thickness of the prisms ensures low IR absorption of sunlight in comparison with acrylic Fresnel lenses. Temperature dependences of the optical properties in such a type of the solar concentrators and PV properties of the cells in passive heat dissipation conditions are under consideration. The solar cells are the triple-junction InGaP/(In)GaAs/Ge cells with designated illumination area 1.7-2.3 mm in diameter. A HCPV module consists of the 144 (or 64) sub-modules in 12x12 (or 8x8) configuration. Solar cells are protected from environment in different ways: by side walls of a module body, or by a rear glass sheet at integrated sealing the cells in a back-side module panel. Module design includes refractive smooth-surface secondary lenses. The cell strings are glued to the rear glass surface of the module body using lamination process. Proper quality of the solar cells in a multistage module assembling procedure is ensured owing to specially developed contactless test method, based on analyzing the electroluminescent signals at local photoexitation. For arrangement of the HCPV modules in a solar installation, a number of the solar trackers have been developed and realized for 1-3-5 kWp of the installed power.

MPPT-Based Solar Powered Water Pumping With RMS

2021 ◽  
pp. 194-224
Author(s):  
Sushri Mukherjee ◽  
Sumana Chattaraj ◽  
Dharmbir Prasad ◽  
Rudra Pratap Singh ◽  
Md Irfan Khan
Keyword(s):  
Agricultural Sector ◽  
High Efficiency ◽  
Cost Effective ◽  
Maximum Power ◽  
The Internet ◽  
Point Tracking ◽  
Power Point Tracking ◽  
Solar Powered ◽  
Power Point ◽  
The Way

In the present era of technology drift, the Internet of Things (IoT) is a promising technology that shows the considerable transition from enterprises to businesses. In this context, renewable energy has played critical roles in developing the agricultural sector with its functionality to generate power over distant areas and different terrain. There has been a transformation in the way we consume electricity and the way it is operated by the utilities. The smart monitoring features are an efficient way to utilize energy and minimize losses. These losses might be the transmission and distribution losses or losses by the inefficient household wiring or appliances. These losses can be minimized if they are monitored well with relevant data and analytics. This book chapter presents an application of the Internet of Energy (IoE) technology in the renewable sector. The study was carried applying Maximum Power Point Tracking (MPPT) functions and corresponding Remote Monitoring System (RMS) functions. The undertaken site for Solar Water Pump (SWP) installation for irrigation is Bihar Sharif (Nalanda, Bihar). The proposed IoE based technology served maximum power output with high efficiency during operating hours. Here, the farmers may do automatic start/shut, remote start/shut from SMS/web with a health check, and self-diagnostic mechanisms for easy maintenance. Thus, the SWP system emerged as a cost-effective and environment-friendly irrigation solution for remote farmers throughout the year. The solar potential assessment of the site and circuital development were done using PVsyst 7.0 and KiCad software tools, respectively. The successful working of the developed product has been observed at the site.

Deposition time dependent study of structural and optical properties of PbS thin films grown by CBD method

2020 ◽  
Vol 13 ◽  
Author(s):  
Minakshi Chaudhary ◽  
Yogesh Hase ◽  
Ashwini Punde ◽  
Pratibha Shinde ◽  
Ashish Waghmare ◽  
...  
Keyword(s):  
Thin Films ◽  
Optical Properties ◽  
Band Gap ◽  
Deposition Time ◽  
Secondary Growth ◽  
Cost Effective ◽  
Xrd Analysis ◽  
Structural Morphology ◽  
Glass Substrates ◽  
Cbd Method

: Thin films of PbS were prepared onto glass substrates by using a simple and cost effective CBD method. Influence of deposition time on structural, morphology and optical properties have been investigated systematically. The XRD analysis revealed that PbS films are polycrystalline with preferred orientation in (200) direction. Enhancement in crystallinity and PbS crystallite size has been observed with increase in deposition time. Formation of single phase PbS thin films has been further confirmed by Raman spectroscopy. The surface morphology analysis revealed the formation of prismatic and pebble-like PbS particles and with increase in deposition time these PbS particles are separated from each other without secondary growth. The data obtained from the EDX spectra shows the formation of high-quality but slightly sulfur rich PbS thin films over the entire range of deposition time studied. All films show increase in absorption with increase in deposition time and a strong absorption in the visible and sub-band gap regime of NIR range of the spectrum with red shift in band edge. The optical band gap shows decreasing trend, as deposition time increases but it is higher than the band gap of bulk PbS.

scholarly journals Chemical Modification of Combusted Coal Gangue for U(VI) Adsorption: Towards a Waste Control by Waste Strategy

2021 ◽  
Vol 13 (15) ◽  
pp. 8421
Author(s):  
Yuan Gao ◽  
Jiandong Huang ◽  
Meng Li ◽  
Zhongran Dai ◽  
Rongli Jiang ◽  
...  
Keyword(s):  
Structural Analysis ◽  
High Efficiency ◽  
Low Cost ◽  
Chemical Activation ◽  
Cost Effective ◽  
Coal Gangue ◽  
Order Kinetic ◽  
Practical Applications ◽  
Detailed Structural Analysis ◽  
Alkaline Conditions

Uranium mining waste causes serious radiation-related health and environmental problems. This has encouraged efforts toward U(VI) removal with low cost and high efficiency. Typical uranium adsorbents, such as polymers, geopolymers, zeolites, and MOFs, and their associated high costs limit their practical applications. In this regard, this work found that the natural combusted coal gangue (CCG) could be a potential precursor of cheap sorbents to eliminate U(VI). The removal efficiency was modulated by chemical activation under acid and alkaline conditions, obtaining HCG (CCG activated with HCl) and KCG (CCG activated with KOH), respectively. The detailed structural analysis uncovered that those natural mineral substances, including quartz and kaolinite, were the main components in CCG and HCG. One of the key findings was that kalsilite formed in KCG under a mild synthetic condition can conspicuous enhance the affinity towards U(VI). The best equilibrium adsorption capacity with KCG was observed to be 140 mg/g under pH 6 within 120 min, following a pseudo-second-order kinetic model. To understand the improved adsorption performance, an adsorption mechanism was proposed by evaluating the pH of uranyl solutions, adsorbent dosage, as well as contact time. Combining with the structural analysis, this revealed that the uranyl adsorption process was mainly governed by chemisorption. This study gave rise to a utilization approach for CCG to obtain cost-effective adsorbents and paved a novel way towards eliminating uranium by a waste control by waste strategy.

scholarly journals Optical spin-symmetry breaking for high-efficiency directional helicity-multiplexed metaholograms

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Muhammad Ashar Naveed ◽  
Muhammad Afnan Ansari ◽  
Inki Kim ◽  
Trevon Badloe ◽  
Joohoon Kim ◽  
...  
Keyword(s):  
High Efficiency ◽  
Spin Symmetry ◽  
Cost Effective ◽  
Dielectric Materials ◽  
Additional Degree ◽  
Cost Effective Alternative ◽  
Spin Orbit Interactions ◽  
Smart Mobile ◽  
The Cost ◽  
Hydrogenated Amorphous

AbstractHelicity-multiplexed metasurfaces based on symmetric spin–orbit interactions (SOIs) have practical limits because they cannot provide central-symmetric holographic imaging. Asymmetric SOIs can effectively address such limitations, with several exciting applications in various fields ranging from asymmetric data inscription in communications to dual side displays in smart mobile devices. Low-loss dielectric materials provide an excellent platform for realizing such exotic phenomena efficiently. In this paper, we demonstrate an asymmetric SOI-dependent transmission-type metasurface in the visible domain using hydrogenated amorphous silicon (a-Si:H) nanoresonators. The proposed design approach is equipped with an additional degree of freedom in designing bi-directional helicity-multiplexed metasurfaces by breaking the conventional limit imposed by the symmetric SOI in half employment of metasurfaces for one circular handedness. Two on-axis, distinct wavefronts are produced with high transmission efficiencies, demonstrating the concept of asymmetric wavefront generation in two antiparallel directions. Additionally, the CMOS compatibility of a-Si:H makes it a cost-effective alternative to gallium nitride (GaN) and titanium dioxide (TiO2) for visible light. The cost-effective fabrication and simplicity of the proposed design technique provide an excellent candidate for high-efficiency, multifunctional, and chip-integrated demonstration of various phenomena.

scholarly journals Near quantitative synthesis of urea macrocycles enabled by bulky N-substituent

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Yingfeng Yang ◽  
Hanze Ying ◽  
Zhixia Li ◽  
Jiang Wang ◽  
Yingying Chen ◽  
...  
Keyword(s):  
High Efficiency ◽  
Molecular Structures ◽  
High Yield ◽  
Kinetic Control ◽  
High Concentration ◽  
Weak Association ◽  
Quantitative Synthesis ◽  
Thermodynamic Stabilization ◽  
Discrete Structures ◽  
Very High

AbstractMacrocycles are unique molecular structures extensively used in the design of catalysts, therapeutics and supramolecular assemblies. Among all reactions reported to date, systems that can produce macrocycles in high yield under high reaction concentrations are rare. Here we report the use of dynamic hindered urea bond (HUB) for the construction of urea macrocycles with very high efficiency. Mixing of equal molar diisocyanate and hindered diamine leads to formation of macrocycles with discrete structures in nearly quantitative yields under high concentration of reactants. The bulky N-tert-butyl plays key roles to facilitate the formation of macrocycles, providing not only the kinetic control due to the formation of the cyclization-promoting cis C = O/tert-butyl conformation, but also possibly the thermodynamic stabilization of macrocycles with weak association interactions. The bulky N-tert-butyl can be readily removed by acid to eliminate the dynamicity of HUB and stabilize the macrocycle structures.

scholarly journals Elucidation of the Crystal Growth Characteristics of SnO2 Nanoaggregates Formed by Sequential Low-Temperature Sol-Gel Reaction and Freeze Drying

Nanomaterials ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1738
Author(s):  
Saeid Vafaei ◽  
Alexander Wolosz ◽  
Catlin Ethridge ◽  
Udo Schnupf ◽  
Nagisa Hattori ◽  
...  
Keyword(s):  
Crystal Growth ◽  
Low Temperature ◽  
Photoelectron Spectroscopy ◽  
High Performance ◽  
Freeze Drying ◽  
Sno2 Nanoparticles ◽  
Sol Gel ◽  
Functional Materials ◽  
Cost Effective ◽  
High Concentration

SnO2 nanoparticles are regarded as attractive, functional materials because of their versatile applications. SnO2 nanoaggregates with single-nanometer-scale lumpy surfaces provide opportunities to enhance hetero-material interfacial areas, leading to the performance improvement of materials and devices. For the first time, we demonstrate that SnO2 nanoaggregates with oxygen vacancies can be produced by a simple, low-temperature sol-gel approach combined with freeze-drying. We characterize the initiation of the low-temperature crystal growth of the obtained SnO2 nanoaggregates using high-resolution transmission electron microscopy (HRTEM). The results indicate that Sn (II) hydroxide precursors are converted into submicrometer-scale nanoaggregates consisting of uniform SnO2 spherical nanocrystals (2~5 nm in size). As the sol-gel reaction time increases, further crystallization is observed through the neighboring particles in a confined part of the aggregates, while the specific surface areas of the SnO2 samples increase concomitantly. In addition, X-ray photoelectron spectroscopy (XPS) measurements suggest that Sn (II) ions exist in the SnO2 samples when the reactions are stopped after a short time or when a relatively high concentration of Sn (II) is involved in the corresponding sol-gel reactions. Understanding this low-temperature growth of 3D SnO2 will provide new avenues for developing and producing high-performance, photofunctional nanomaterials via a cost-effective and scalable method.

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