scholarly journals Advances in High-Efficiency III-V Multijunction Solar Cells

2007 ◽  
Vol 2007 ◽  
pp. 1-8 ◽  
Author(s):  
Richard R. King ◽  
Daniel C. Law ◽  
Kenneth M. Edmondson ◽  
Christopher M. Fetzer ◽  
Geoffrey S. Kinsey ◽  
...  

The high efficiency of multijunction concentrator cells has the potential to revolutionize the cost structure of photovoltaic electricity generation. Advances in the design of metamorphic subcells to reduce carrier recombination and increase voltage, wide-band-gap tunnel junctions capable of operating at high concentration, metamorphic buffers to transition from the substrate lattice constant to that of the epitaxial subcells, concentrator cell AR coating and grid design, and integration into 3-junction cells with current-matched subcells under the terrestrial spectrum have resulted in new heights in solar cell performance. A metamorphic Ga0.44In0.56P/Ga0.92In0.08As/ Ge 3-junction solar cell from this research has reached a record 40.7% efficiency at 240 suns, under the standard reporting spectrum for terrestrial concentrator cells (AM1.5 direct, low-AOD, 24.0 W/cm2, 25∘C), and experimental lattice-matched 3-junction cells have now also achieved over 40% efficiency, with 40.1% measured at 135 suns. This metamorphic 3-junction device is the first solar cell to reach over 40% in efficiency, and has the highest solar conversion efficiency for any type of photovoltaic cell developed to date. Solar cells with more junctions offer the potential for still higher efficiencies to be reached. Four-junction cells limited by radiative recombination can reach over 58% in principle, and practical 4-junction cell efficiencies over 46% are possible with the right combination of band gaps, taking into account series resistance and gridline shadowing. Many of the optimum band gaps for maximum energy conversion can be accessed with metamorphic semiconductor materials. The lower current in cells with 4 or more junctions, resulting in lower I2R resistive power loss, is a particularly significant advantage in concentrator PV systems. Prototype 4-junction terrestrial concentrator cells have been grown by metal-organic vapor-phase epitaxy, with preliminary measured efficiency of 35.7% under the AM1.5 direct terrestrial solar spectrum at 256 suns.

1996 ◽  
Vol 452 ◽  
Author(s):  
P. Pemet ◽  
M. Goetz ◽  
H. Keppner ◽  
A. Shah

AbstractThe <p> μc-SiC:H / <i> a-Si:H junction can be considered to be a sub-system of a n/i/p solar cell. Optimised performance of this junction can be assumed to be a key feature for obtaining high efficiency solar cells.In this paper the authors present results on the conductivity of boron doped microcrystalline hydrogenated silicon (<p> μc-Si:H) thin films deposited on amorphous substrates (e.g. glass or glass/<i> a-Si:H). It is shown that, without any treatment of the substrate or of the underlying surface, the <p> layers showed a strongly reduced conductivity. This indicates either a bad nucleation or a poor microcrystalline behaviour. By using an appropriate surface treatment of the substrate, a gain in photoconductivity of about three orders of magnitude could be obtained (σ > 3 S/cm at a layer thickness of 400Å). We conclude from this, that for thin <p> type μc-Si:H layers the nucleation conditions are essential for obtaining best electric properties of the film w.r.t. solar cell performance.Based on these results, interface treatment was successfully implemented in n/i/p solar cells deposited on TCO coated glass and stainless steel. The results of these experiments are also presented.


1999 ◽  
Vol 557 ◽  
Author(s):  
J. Yang ◽  
S. Guha

AbstractOne of the most effective techniques used to obtain high quality amorphous silicon alloys is the use of hydrogen dilution during film growth. The resultant material exhibits a more ordered microstructure and gives rise to high efficiency solar cells. As the hydrogen dilution increases, however, a threshold is reached, beyond which microcrystallites begin to form rapidly. In this paper, we review some of the interesting features associated with the thin film materials obtained from various hydrogen dilutions. They include the observation of linear-like objects in the TEM micrograph, a shift of the principal Si TO band in the Raman spectrum, a sharp, low temperature peak in the H2 evolution spectrum, a shift of the wagging mode in the IR spectrum, and a narrowing of the Si (111) peak in the X-ray diffraction pattern. These spectroscopic tools have allowed us to optimize deposition conditions to near the threshold of microcrystallinity and obtain desired high quality materials. Incorporation of the improved materials into device configuration has significantly enhanced the solar cell performance. Using a spectral-splitting, triple-junction configuration, the spectral response of a typical high efficiency device spans from below 350 nm to beyond 950 nm with a peak quantum efficiency exceeding 90%; the triple stack generates a photocurrent of 27 mA/cm2. This paper describes the effect of the improved materials on various solar cell structures, including a 13% active-area, stable triple-junction device.


Author(s):  
Satya Narayan Mourya ◽  
Pankaj Gupta ◽  
Skand Trivedi

The three dimensional photovoltaic cell is revolutionary silicon solar cell, design to maximize the conversion of sunlight into electricity. It is like container rather than plane conventional solar cell and has ‘High Efficiency Design to produce 200% of the Power Output of the Conventional Solar Cells’. Three dimensional solar has a special feature on the surface to capture more light in the morning and evening hours, as well as in the winter months when the sun is not directly overhead. Unlike conventional solar cells where electrical contact wires run on the top of the cell, blocking sunlight, three dimensional solar cell use a network of contact wires run below the light collector. Solar Tree is energy generating and harvesting tree, in order to increase efficiency “SPIRALLING PHYLLATAXY” technique is applied. It is way of mounting the three dimensional solar panel (leaf) on the top such a way that maximum sunlight incident on it. It can be applied in street lightening system, industrial power supply etc. It is much better than traditional photovoltaic solar system in area point of viewandalso more efficient. It is perfect solution for future energy needandFibonacci Sequence SolarTree is one of advance solar tree. After using three dimensional solar cell in solar tree, the investment payback period of solar panel systems is40%more than conventional solar panel systems.


2012 ◽  
Vol 476-478 ◽  
pp. 1815-1819 ◽  
Author(s):  
Jing Wei Chen ◽  
Lei Zhao ◽  
Su Zhou ◽  
Hong Wei Diao ◽  
Ye Hua Tang ◽  
...  

Pyramidal texture is one traditional method to realize antireflection for c-Si solar cells, due to its low cost and simplicity. As one high efficiency silicon solar cell, amorphous/crystalline silicon heterojunction (SHJ) solar cell has attracted much attention all over the world. The heterojunction interface with very low defects and interface states is critical to the SHJ solar cell performance. In order to obtain high quality interface passivation by depositing a very thin intrinsic amorphous silicon layer on the textured Si conformally, large size pyramidal texture with no metal ion contamination is required. In this work, we utilized tetra-methyl ammonium hydroxide (TMAH) instead of NaOH in the alkaline etching to prepare pyramidal texture on N-type monocrystalline silicon to avoid the possible Na+ contamination. By optimizing the etching conditions, uniform large size pyramidal texture with pyramid size of about 10 μm was fabricated successfully. Furthermore, excellent antireflection performance was demonstrated on such textured Si surface. The average reflectance was lower than 10% in the visible and near infrared spectrum range. Such pyramidally textured Si wafers will be very suitable for SHJ solar cells.


2021 ◽  
Vol 12 (1) ◽  
pp. 83
Author(s):  
Ha Trang Nguyen ◽  
Thanh Thao Tran ◽  
Vishwa Bhatt ◽  
Manjeet Kumar ◽  
Jinwon Song ◽  
...  

Recently, in the solar energy society, several key technologies have been reported to meet a grid parity, such as cost-efficient materials, simple processes, and designs. Among them, the assistive plasmonic of metal nanoparticles (MNPs) integrating with the downshifting on luminescent materials attracts much attention. Hereby, Si-based Schottky junction solar cells are fabricated and examined to enhance the performance. CdSe/ZnS quantum dots (QDs) with different gold nanoparticles (Au NPs) sizes were incorporated on a Si light absorbing layer. Due to the light scattering effect from plasmonic resonance, the sole Au NPs layer results in the overall enhancement of Si solar cell’s efficiency in the visible spectrum. However, the back-scattering and high reflectance of Au NPs lead to efficiency loss in the UV region. Therefore, the QDs layer acting as a luminescent downshifter is deployed for further efficiency enhancement. The QDs layer absorbs high-energy photons and re-emits lower energy photons in 528 nm of wavelength. Such a downshift layer can enhance the overall efficiency of Si solar cells due to poor intrinsic spectral response in the UV region. The optical properties of Au NPs and CdSe QDs, along with the electrical properties of solar cells in combination with Au/QD layers, are studied in depth. Moreover, the influence of Au NPs size on the solar cell performance has been investigated. Upon decreasing the diameters of Au NPs, the blueshift of absorbance has been observed, cooperating with QDs, which leads to the improvement of the quantum efficiency in the broadband of the solar spectrum.


Nanomaterials ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 2911
Author(s):  
Inês Margarida Pinheiro Caetano ◽  
João Paulo N. Torres ◽  
Ricardo A. Marques Lameirinhas

The evolution of nanotechnology has provided a better understanding of light-matter interaction at a subwavelength scale and has led to the development of new devices that can possibly play an important role in future applications. Nanoantennas are an example of such devices, having gained interest in recent years for their application in the field of photovoltaic technology at visible and infrared wavelengths, due to their ability to capture and confine energy of free-propagating waves. This property results from a unique phenomenon called extraordinary optical transmission (EOT) where, due to resonant behavior, light passing through subwavelength apertures in a metal film can be transmitted in greater orders of magnitude than that predicted by classical theories. During this study, 2D and 3D models featuring a metallic nanoantenna array with subwavelength holes coupled to a photovoltaic cell are simulated using a Finite Element Tool. These models present with slight variations between them, such as the position of the nanoantenna within the structure, the holes’ geometry and the type of cell, in order to verify how its optical response is affected. The results demonstrate that the coupling of nanoantennas to solar cells can be advantageous and improve the capture and absorption of radiation. It is concluded that aperture nanoantennas may concentrate radiation, meaning that is possible to tune the electric field peak and adjust absorption on the main layers. This may be important because it might be possible to adjust solar cell performance to the global regions’ solar spectrum by only adjusting the nanoantenna parameters.


2018 ◽  
Vol 15 (5) ◽  
pp. 549-555 ◽  
Author(s):  
Assiya Haddout ◽  
Abderrahim Raidou ◽  
Mounir Fahoume

Purpose The purpose of this paper is to study the effect of individual layers of cadmium telluride (CdTe) solar cell to improve the efficiency of the photovoltaic cell. Design/methodology/approach To improve the performances of CdTe thin-film solar cells, the thickness of CdTe and cadmium sulfide (CdS) have been modified separately. High-efficiency ultra-thin CdTe solar cell with ZnTe layer as back surface field (BSF) was achieved. The CdTe solar cell is under AM1.5 g illumination using a one-dimensional (1-D) model, i.e. personal computer one dimensional (PC1D). Findings The highest conversion efficiency of about 15.3 per cent was achieved for ultrathin CdTe solar cell with a ZnTe BSF layer. The results of simulation were compared with experimental and analytical results by other researchers. Originality/value In this paper, according to the authors’ knowledge ZnO:Al/CdS/CdTe/ZnTe is simulated by PC1D model for the first time and is compared with experimental result (ZnO:Al/CdS/CdTe). The results show a suitable performance.


Author(s):  
Muhammad Hassan Yousuf ◽  
Faisal Saeed ◽  
Haider Ali Tauqeer

Copper indium gallium selenide (CIGS) is an inexpensive material that has the potential to dominate the next-generation photovoltaic (PV) industry. Here we detail computational investigation of CIGS solar cell with encouragement of adopting cuprous dioxide (Cu2O) as a Hole Transport Layer (HTL) for efficient fabricated CIGS solar cells. Although Cu2O as a HTL has been studied earlier for perovskite and other organic/inorganic solar cell yet no study has been detailed on potential application of Cu2O for CIGS solar cells. With the proposed architecture, recombination losses are fairly reduced at the back contact and contribute to enhanced photo-current generation. With the introduction of Cu2O, the overall cell efficiency is increased to 26.63%. The wide-band of Cu2O pulls holes from the CIGS absorber which allows smoother extraction of holes with experiencing lesser resistance. Further, it was also inferred that, HTL also improves the quantum efficiency (QE) for photons with large wavelengths thus increases the cell operating spectrum.


Crystals ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1468
Author(s):  
Samer H. Zyoud ◽  
Ahed H. Zyoud ◽  
Naser M. Ahmed ◽  
Anupama R. Prasad ◽  
Sohaib Naseem Khan ◽  
...  

The numerical modeling of a copper zinc tin sulfide (CZTS)-based kesterite solar cell is described in detail in this article. To model FTO/ZnO/CdS/CZTS/MO structured solar cells, the Solar Cell Capacitance Simulator-one-dimension (SCAPS-1D) program was utilized. Numerical modeling was used to estimate and assess the parameters of various photovoltaic thin film solar cells. The impact of different parameters on solar cell performance and conversion efficiency were explored. Because the response of a solar cell is partly determined by its internal physical mechanism, J-V characteristic characteristics are insufficient to define a device’s behavior. Regardless of the conviction in solar cell modeling, variable attributes as well as many probable conditions must be handled for simulation. Promising optimized results were obtained with a conversion efficiency of (η% = 25.72%), a fill factor of (FF% = 83.75%), a short-circuit current of (JSC  = 32.96436 mA/cm2), and an open-circuit voltage of (VOC = 0.64 V). The findings will aid in determining the feasibility of manufacturing high-efficiency CZTS-based solar cells. First, in the SCAPS-1D environment, the impacts of experimentally constructed CZTS solar cells were simulated. The experimental data was then compared to the simulated results from SCAPS-1D. After optimizing cell parameters, the conversion efficiency of the improved system was observed to rise. The influence of system factors, such as the thickness, acceptor, and donor carrier concentration densities of the absorber and electron transport layers, and the effect of temperature on the efficiency of CZTS-based photovoltaic cells, was explored using one-dimensional SCAPS-1D software. The suggested findings will be extremely useful to engineers and researchers in determining the best method for maximizing solar cell efficiency, as well as in the development of more efficient CZTS-based solar cells.


2007 ◽  
Vol 989 ◽  
Author(s):  
Florian Einsele ◽  
Phillip Johannes Rostan ◽  
Uwe Rau

AbstractWe study resistive losses at (p)c-Si/(p)Si:H/(n)ZnO heterojunction back contacts for high efficiency silicon solar cells. We find that a low tunnelling resistance for the (p)a-Si:H/(n)ZnO part of the junction requires deposition of Si:H with a high hydrogen dilution RH > 40 resulting in a highly doped μc-Si:H layer. Such a μc-Si:H layer if deposited directly on a Si wafer yields a surface recombination velocity of S  180 cm/s. Using the same layer as part of a (p)c-Si/(p)Si:H/(n)ZnO back contact in a solar cell results in an open circuit voltage Voc = 640 mV and a fill factor FF = 80 %. Insertion of an (i)a-Si-layer between the μc-Si:H and the wafer leads to a further decrease of S and, for the solar cells to an increase of VOC. However, if the thickness of this intrinsic layer exceeds a threshold of 3 nm, resistive losses lead to a degradation of the fill factor of the solar cells. These resistive losses result from a valence band offset δEV between a-Si:H and c-Si of about 600 meV. The fill factor losses overcompensate the VOC gain such that there is no benefit of the (i)a-Si:H interlayer for the overall solar cell performance when using an (i)a-Si:H/(p)uc-Si:H double layer.


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