Research

Jump to: Review

491 KiB

Open AccessArticle

Hybrid Dielectric-Metallic Back Reflector for Amorphous Silicon Solar Cells

by James G. Mutitu, Shouyuan Shi, Allen Barnett and Dennis W. Prather

Energies 2010, 3(12), 1914-1933; https://doi.org/10.3390/en3121914 - 10 Dec 2010

Cited by 19 | Viewed by 10499

In this paper, we present the design and fabrication of hybrid dielectric-metallic back surface reflectors, for applications in thin film amorphous silicon solar cells. Standard multilayer distributed Bragg reflectors, require a large number of layers in order to achieve high reflectance characteristics. As [...] Read more.

In this paper, we present the design and fabrication of hybrid dielectric-metallic back surface reflectors, for applications in thin film amorphous silicon solar cells. Standard multilayer distributed Bragg reflectors, require a large number of layers in order to achieve high reflectance characteristics. As it turns out, the addition of a metallic layer, to the base of such a multilayer mirror, enables a reduction in the number of dielectric layers needed to attain high reflectance performance. This paper explores the design, experimental realization and opportunities, in thin film amorphous silicon solar cells, afforded by such hybrid dielectric-metallic back surface reflectors. Full article

(This article belongs to the Special Issue Solar Cells)

► Show Figures

Graphical abstract

667 KiB

Open AccessArticle

Fabrication and Characterization of Fullerene-Based Bulk Heterojunction Solar Cells with Porphyrin, CuInS2, Diamond and Exciton-Diffusion Blocking Layer

by Takeo Oku, Akihiro Takeda, Akihiko Nagata, Tatsuya Noma, Atsushi Suzuki and Kenji Kikuchi

Energies 2010, 3(4), 671-685; https://doi.org/10.3390/en3040671 - 08 Apr 2010

Cited by 34 | Viewed by 9860

Abstract

Fullerene-based bulk heterojunction solar cells were fabricated, and the electronic and optical properties were investigated. C₆₀ were used as n-type semiconductors, and porphyrin, CuInS₂ and diamond were used as p-type semiconductors. An effect of exciton-diffusion blocking layer of perylene derivative on [...] Read more.

Fullerene-based bulk heterojunction solar cells were fabricated, and the electronic and optical properties were investigated. C₆₀ were used as n-type semiconductors, and porphyrin, CuInS₂ and diamond were used as p-type semiconductors. An effect of exciton-diffusion blocking layer of perylene derivative on the solar cells between active layer and metal layer was also investigated. Optimized structures with the exciton-diffusion blocking layer improved conversion efficiencies. Electronic structures of the molecules were investigated by molecular orbital calculation, and energy levels of the solar cells were discussed. Nanostructures of the solar cells were investigated by transmission electron microscopy, electron diffraction and X-ray diffraction, which indicated formation of mixed nanocrystals. Full article

(This article belongs to the Special Issue Solar Cells)

► Show Figures

Figure 1

653 KiB

Open AccessArticle

Comparison of Hybrid Blends for Solar Cell Application

by Maria C. Lechmann, Dominik Koll, Daniel Kessler, Patrick Theato, Wolfgang Tremel and Jochen S. Gutmann

Energies 2010, 3(3), 301-312; https://doi.org/10.3390/en3030301 - 05 Mar 2010

Cited by 8 | Viewed by 10822

Abstract

In blended hybrid systems distinct micro- or nanostructured materials can be formed by phase separation. Network structures of particles or rods in a polymer matrix can be developed via self-assembly. We use this blending approach to compare active materials for application in solar [...] Read more.

In blended hybrid systems distinct micro- or nanostructured materials can be formed by phase separation. Network structures of particles or rods in a polymer matrix can be developed via self-assembly. We use this blending approach to compare active materials for application in solar cell devices. Blends were fabricated from either poly(hexylthiophene) P3HT or poly(triphenylamine) PTPA mixed with nanocrystalline TiO₂ rods. In this manner, we compare two different hole conducting polymers in their performance in photovoltaic devices, while experimental conditions are kept identical. We find that the choice of solvent and photovoltaic characterization conducted in inert atmosphere is of importance for blends prepared from P3HT/TiO₂ blends, but not for PTPA/TiO₂ blends. Even though prepared with the same TiO₂ rods, solar cells prepared from PTPA blends showed an enhanced efficiency when measured under ambient conditions. Furthermore, the PTPA/TiO₂ showed higher long-term stability. Full article

(This article belongs to the Special Issue Solar Cells)

► Show Figures

Figure 1

Review

Jump to: Research

509 KiB

Open AccessReview

Designs and Architectures for the Next Generation of Organic Solar Cells

by Kang-Shyang Liao, Soniya D. Yambem, Amrita Haldar, Nigel J. Alley and Seamus A. Curran

Energies 2010, 3(6), 1212-1250; https://doi.org/10.3390/en3061212 - 14 Jun 2010

Cited by 63 | Viewed by 14202

Abstract

Organic solar cells show great promise as an economically and environmentally friendly technology to utilize solar energy because of their simple fabrication processes and minimal material usage. However, new innovations and breakthroughs are needed for organic solar cell technology to become competitive in [...] Read more.

Organic solar cells show great promise as an economically and environmentally friendly technology to utilize solar energy because of their simple fabrication processes and minimal material usage. However, new innovations and breakthroughs are needed for organic solar cell technology to become competitive in the future. This article reviews research efforts and accomplishments focusing on three issues: power conversion efficiency, device stability and processability for mass production, followed by an outlook for optimizing OSC performance through device engineering and new architecture designs to realize next generation organic solar cells. Full article

(This article belongs to the Special Issue Solar Cells)

► Show Figures

Figure 1

1386 KiB

Open AccessReview

Efficiently Harvesting Sun Light for Silicon Solar Cells through Advanced Optical Couplers and A Radial p-n Junction Structure

by Hsin-Cheng Lee, Shich-Chuan Wu, Tien-Chung Yang and Ta-Jen Yen

Energies 2010, 3(4), 784-802; https://doi.org/10.3390/en3040784 - 20 Apr 2010

Cited by 17 | Viewed by 11065

Abstract

Silicon-based solar cells (SCs) promise to be an alternative energy source mainly due to: (1) a high efficiency-to-cost ratio, (2) the absence of environmental-degradation issues, and (3) great reliability. Transition from wafer-based to thin-film SC significantly reduces the cost of SCs, including the [...] Read more.

Silicon-based solar cells (SCs) promise to be an alternative energy source mainly due to: (1) a high efficiency-to-cost ratio, (2) the absence of environmental-degradation issues, and (3) great reliability. Transition from wafer-based to thin-film SC significantly reduces the cost of SCs, including the cost from the material itself and the fabrication process. However, as the thickness of the absorption (or the active) layer decreases, the energy-conversion efficiency drops dramatically. As a consequence, we discuss here three techniques to increase the efficiency of silicon-based SCs: (1) photonic crystal (PC) optical couplers and (2) plasmonic optical couplers to increase efficiency of light absorption in the SCs, and (3) a radial p-n junction structure, decomposing light absorption and diffusion path into two orthogonal directions. The detailed mechanisms and recent research progress regarding these techniques are discussed in this review article. Full article

(This article belongs to the Special Issue Solar Cells)

► Show Figures

Figure 1

1427 KiB

Open AccessReview

Organic / IV, III-V Semiconductor Hybrid Solar Cells

by Pang-Leen Ong and Igor A. Levitsky

Energies 2010, 3(3), 313-334; https://doi.org/10.3390/en3030313 - 05 Mar 2010

Cited by 69 | Viewed by 14113

Abstract

We present a review of the emerging class of hybrid solar cells based on organic-semiconductor (Group IV, III-V), nanocomposites, which states separately from dye synthesized, polymer-metal oxides and organic-inorganic (Group II-VI) nanocomposite photovoltaics. The structure of such hybrid cell comprises of an organic [...] Read more.

We present a review of the emerging class of hybrid solar cells based on organic-semiconductor (Group IV, III-V), nanocomposites, which states separately from dye synthesized, polymer-metal oxides and organic-inorganic (Group II-VI) nanocomposite photovoltaics. The structure of such hybrid cell comprises of an organic active material (p-type) deposited by coating, printing or spraying technique on the surface of bulk or nanostructured semiconductor (n-type) forming a heterojunction between the two materials. Organic components include various photosensitive monomers (e.g., phtalocyanines or porphyrines), conjugated polymers, and carbon nanotubes. Mechanisms of the charge separation at the interface and their transport are discussed. Also, perspectives on the future development of such hybrid cells and comparative analysis with other classes of photovoltaics of third generation are presented. Full article

(This article belongs to the Special Issue Solar Cells)

► Show Figures

Figure 1

2846 KiB

Open AccessReview

Complex Nanostructures: Synthesis and Energetic Applications

by Xiaohua Liu, Yongjing Lin, Sa Zhou, Stafford Sheehan and Dunwei Wang

Energies 2010, 3(3), 285-300; https://doi.org/10.3390/en3030285 - 26 Feb 2010

Cited by 29 | Viewed by 9491

Abstract

Connected through single crystalline junctions, low dimensional materials such as nanowires and nanorods form complex nanostructures. These new materials exhibit mechanical strengths and electrical conductivities superior to their constituents while maintaining comparable surface areas, an attribute ideal for energetic applications. More efficient solar [...] Read more.

Connected through single crystalline junctions, low dimensional materials such as nanowires and nanorods form complex nanostructures. These new materials exhibit mechanical strengths and electrical conductivities superior to their constituents while maintaining comparable surface areas, an attribute ideal for energetic applications. More efficient solar cells, higher capacity batteries and better performing photoelectrochemical cells have been built using these materials. This article reviews this exciting new class of materials and covers topics from controlled syntheses to applications in photovoltaics, chemical energy conversion and electrical charge storage. Mechanisms responsible for the improved performance are discussed. The prospect of their applications in a broader energy-related field is analyzed. Full article

(This article belongs to the Special Issue Solar Cells)

► Show Figures

Figure 1

2318 KiB

Open AccessReview

Spectrally-Selective Photonic Structures for PV Applications

by Marius Peters, Jan Christoph Goldschmidt, Philipp Löper, Bernhard Groß, Johannes Üpping, Frank Dimroth, Ralf B. Wehrspohn and Benedikt Bläsi

Energies 2010, 3(2), 171-193; https://doi.org/10.3390/en3020171 - 27 Jan 2010

Cited by 65 | Viewed by 14305

Abstract

We review several examples of how spectrally-selective photonic structures may be used to improve solar cell systems. Firstly, we introduce different spectrally-selective structures that are based on interference effects. Examples shown include Rugate filter, edge filter and 3D photonic crystals such as artificial [...] Read more.

We review several examples of how spectrally-selective photonic structures may be used to improve solar cell systems. Firstly, we introduce different spectrally-selective structures that are based on interference effects. Examples shown include Rugate filter, edge filter and 3D photonic crystals such as artificial opals. In the second part, we discuss several examples of photovoltaic (PV) concepts that utilize spectral selectivity such as fluorescence collectors, upconversion systems, spectrum splitting concepts and the intermediate reflector concept. The potential of spectrally selective filters in the context of solar cells is discussed. Full article

(This article belongs to the Special Issue Solar Cells)

► Show Figures

Figure 1

781 KiB

Open AccessReview

Energy Storage in Bifunctional TiO₂ Composite Materials under UV and Visible Light

by Liangbin Xiong, Jialin Li and Ying Yu

Energies 2009, 2(4), 1009-1030; https://doi.org/10.3390/en20401009 - 06 Nov 2009

Cited by 13 | Viewed by 10531

Abstract

This paper provides an overview of recent studies on energy storage in bifunctional TiO₂ composite materials under UV and visible light. The working mechanism, property improvements and applications of these bifunctional TiO₂composite systems are introduced, respectively. The latest results obtained [...] Read more.

This paper provides an overview of recent studies on energy storage in bifunctional TiO₂ composite materials under UV and visible light. The working mechanism, property improvements and applications of these bifunctional TiO₂composite systems are introduced, respectively. The latest results obtained in our laboratory, especially a new process for photoelectric conversion and energy storage in TiO₂/Cu₂O bilayer films under visible light, are also presented. Hopefully this review will stimulate more fundamental and applied research on this subject in the future. Full article

(This article belongs to the Special Issue Solar Cells)

► Show Figures

Figure 1

699 KiB

Open AccessReview

A Review of Ultrahigh Efficiency III-V Semiconductor Compound Solar Cells: Multijunction Tandem, Lower Dimensional, Photonic Up/Down Conversion and Plasmonic Nanometallic Structures

by Katsuaki Tanabe

Energies 2009, 2(3), 504-530; https://doi.org/10.3390/en20300504 - 13 Jul 2009

Cited by 143 | Viewed by 25320

Abstract

Solar cells are a promising renewable, carbon-free electric energy resource to address the fossil fuel shortage and global warming. Energy conversion efficiencies around 40% have been recently achieved in laboratories using III-V semiconductor compounds as photovoltaic materials. This article reviews the efforts and [...] Read more.

Solar cells are a promising renewable, carbon-free electric energy resource to address the fossil fuel shortage and global warming. Energy conversion efficiencies around 40% have been recently achieved in laboratories using III-V semiconductor compounds as photovoltaic materials. This article reviews the efforts and accomplishments made for higher efficiency III-V semiconductor compound solar cells, specifically with multijunction tandem, lower-dimensional, photonic up/down conversion, and plasmonic metallic structures. Technological strategies for further performance improvement from the most efficient (Al)InGaP/(In)GaAs/Ge triple-junction cells including the search for 1.0 eV bandgap semiconductors are discussed. Lower-dimensional systems such as quantum well and dot structures are being intensively studied to realize multiple exciton generation and multiple photon absorption to break the conventional efficiency limit. Implementation of plasmonic metallic nanostructures manipulating photonic energy flow directions to enhance sunlight absorption in thin photovoltaic semiconductor materials is also emerging. Full article

(This article belongs to the Special Issue Solar Cells)

► Show Figures

Graphical abstract

Journal Menu

Journal Browser

Solar Cells

Share This Special Issue

Special Issue Editor

Special Issue Information

Keywords

Related Special Issue

Published Papers (10 papers)

Research

Review

Further Information

Guidelines

MDPI Initiatives

Follow MDPI