Showing papers on "Polymer solar cell published in 1984"

Point-contact silicon solar cells

Abstract: A new type of silicon photovoltaic cell designed for high-concentration applications is presented. The device is called the point-contact-cell and shows potential for achieving energy conversion efficiencies in the neighborhood of 28 percent at the design operating point of 500× geometric concentration and 60°C cell temperature. This cell has alternating n and p regions that form a polkadot array on the bottom surface. A two-layermetallization on the bottom provides contact. Initial experimental results have yielded a cell with 20-percent efficiency at a concentration of 88.

High conversion efficiency and high radiation resistance InP homojunction solar cells

Abstract: InP homojunction solar cells have been fabricated using thermal diffusion of sulphur or selenium into p‐type InP substrates. A conversion efficiency of 16.5% (active area) was obtained for a S‐diffused cell under simulated AM1.5 illumination. The InP solar cell was found for the first time to have a higher resistance to γ‐ray radiation degradation than Si and GaAs solar cells with comparable junction depth. These results show a possibility of the InP solar cells for space applications.

Photovoltaic tandem cell

Abstract: A photovoltaic tandem cell comprises an amorphous cell and a polycrystalline heterojunction cell. The cells are in optical series and separated by a transparent contact layer.

Electron Irradiation Damage in Radiation-Resistant InP Solar Cells

Abstract: In this paper it is shown that InP solar cell is more radiation-resistant than Si and GaAs solar cells. 1 MeV electron irradiation damages in InP solar cells with AM 1.5 conversion efficiencies exceeding 16.5% are examined. Minority carrier diffusion length and carrier concentration studies for defects induced by 1 MeV electron irradiation in InP solar cells are carried out, and the correlation between the measured defect parameters and the performance characteristics of the electron-irradiated InP solar cells are elucidated. InP solar cells with higher carrier concentration substrate are found to be more radiation resistant, which is due to the superior radiation-resistance for the high carrier concentration InP substrate.

Sunlight-into-energy conversion apparatus

Abstract: An apparatus in which amorphous silicon solar cells are formed on a heat collecting plate. The solar cells are formed by using a superstrate or a substrate. Both a light-permeable superstrate and a metallic substrate are available for use. If the light-permeable superstrate is adopted, metallic electrodes, formed on the side of the heat collecting plate as lower electrodes of the solar cells, are attached to the heat collecting plate through electrically insulating adhesives, provided that the upper surface of the superstrate is exposed against the incident sunlight. The light-permeable superstrate is made of a heat absorbing material transmitting light having a wavelength range which is absorbed by the amorphous silicon layer of the solar cells while absorbing light having a wavelength range which is transmitted through the amorphous silicon layer thereby to convert the light into thermal energy. Alternatively, a heat absorbing layer made of a material having the above-mentioned property may be provided on a transparent superstrate. On the other hand, if the metallic substrate is used, the substrate is also available for the heat collecting plate, or is attached to the heat collecting plate while said heat absorbing layer may be provided on transparent electrodes formed on the upper side of the substrate as upper electrodes of the solar cells.

Role of carbon in hydrogenated amorphous silicon solar cell degradation

Abstract: Experiments using a combination of capacitance and photovoltaic transient spectroscopy on hydrogenated amorphous silicon solar cells demonstrate that carbon produces a metastable defect with characteristic energy and emission time. This defect is involved in solar cell degradation.

Gallium arsenide phosphide top solar cell

Abstract: An improved tandem solar cell includes a gallium arsenide phosphide top solar cell and silicon bottom solar cell. The gallium arsenide phosphide solar cell is fabricated on a transparent gallium phosphide substrate and either placed in series with the silicon solar cell for a two terminal device or wired separately for a four terminal device. The top solar cell should have an energy gap between 1.77 and 2.09 eV for optimum energy conversion efficiency. A compositionally graded transition layer between the gallium phosphide substrate and the active semiconductor layers reduces dislocations in the active region. A gallium phosphide cap layer over the gallium arsenide phosphide solar cell reduces surface recombination losses.

Amorphous silicon solar cells fabricated by photochemical vapor deposition

Abstract: Hydrogenated amorphous silicon solar cells were fabricated by photochemical vapor deposition. Wide optical band‐gap (∼2.0 eV) hydrogenated amorphous silicon carbide was employed for the p layer. Acetylene (C2H2) or dimethylsilane (Si(CH3)2H2) was used as a carbon source instead of methane which is usually used in a glow discharge process. Although p, i, and n layers were deposited in a single reaction chamber, the solar cell showed high‐energy conversion efficiency of 8.29% under AM1, 100‐mW/cm2 insolation. The distribution of boron atoms in the solar cell was analyzed by secondary ion mass spectroscopy. The boron content in the i layer was of the order of 1016 cm−3. This is comparable to that in the i layer of the solar cell fabricated by the glow discharge system with separated three reaction chambers.

Solar energy converter employing a fluorescent wavelength shifter

Abstract: Disclosed herein is a solar converter structure and fabrication process therefor which includes a composite zinc selenide fluorescent wavelength shifter (FWS) prepared with anti-reflective (AR) coatings on both major surfaces thereof. One of these AR coatings is adhesively bonded to an AR coating on the sunlight-receiving surface of a gallium arsenide or an aluminum gallium arsenide photovoltaic (PV) solar cell, and the "free-standing" FWS composite wavelength shifter protects the solar cell from proton and ultraviolet radiation damage. The ZnSe wavelength shifter has a spectral response below about 0.47 micrometers and the solar cell has a spectral response above about 0.47 micrometers. The wavelength shifter absorbs radiation in the 0.3 to 0.47 micrometer range and re-emits radiation to the solar cell in a band centered about 0.62 micrometers and well within the pn junction response spectra for the solar cell to thereby enhance its power output.

Amorphous/crystalline heterostructure as a novel approach to fabrication of a solar cell

Abstract: The performance and characteristics of a novel structure device combining amorphous and crystalline semiconductors is reported for the first time. An amorphous SiC:H/crystal Si heterostructure solar cell gave a conversion efficiency of 5.11% with Voc = 0.53 V and Isc = 22.64 mA/cm2 without the use of any transparent electrode or AR coating. The relative spectral response of the cells has been found to be close to that of the ‘violet cell’.

Increased voltage photovoltaic cell

Abstract: A photovoltaic cell, such as a solar cell, is provided which has a higher output voltage than prior cells. The improved cell includes a substrate of doped silicon, a first layer of silicon disposed on the substrate and having opposite doping, and a second layer of silicon carbide disposed on the first layer. The silicon carbide preferably has the same type of doping as the first layer.

An amorphous silicon solar cell having a conversion efficiency of 10.50 percent

Abstract: We report on a hydrogenated amorphous silicon (a-Si:H) p-i-n solar cell having a conversion efficiency of 10.50 percent (1.05-cm2area). The cell was prepared by a conventional plasma-enhanced chemical vapor deposition process using a structure back electrode n-i-p/SnO 2 -ITO/glass. This conversion efficiency was obtained from the reduction and control of impurity levels in the i-layer. Photovoltaic characteristics of prepared cells were measured under AMI (100 mW/cm2). The impurity levels of oxygen and boron were measured by SIMS and are discussed.

Critical processing parameter optimization for screen printed semicrystalline silicon solar cells

Abstract: Optimisation des parametres critiques de fabrication par serigraphie des cellules solaires au silicium polycristallin

Solar cell of amorphous silicon

Abstract: A PIN solar cell of amorphous silicon with a high photovoltaic conversion efficiency is provided, in which in the P type layer, the electric conductivity of a zone in contact with an electrode is higher than that of another zone in contact with the I type layer.

Amorphous silicon solar cells

Abstract: The direct conversion of sunlight into electricity has been a utopian dream. The ability to generate electricity in this manner is, of course, exciting since it utilizes nondepletable fuel and is nonpolluting. However, since the 1950’s, the approach to accomplish this aim has been primarily through the utilization of expensive crystalline silicon solar cells. We describe here how noncrystalline materials, that is, amorphous materials, can be produced as continuous, large‐area, thin‐film devices with efficiencies, stabilities, and costs which will permit them, for the first time, to compete realistically with conventional fuels such as oil, gas, uranium, and coal.

Inverted, optically enhanced solar cell

Abstract: An ultra-high efficiency inverted solar cell structure is disclosed. At the rear of the cell is a high performance heterocontact made of SIPOS (a mixture of micro-crystalline silicon and silicon dioxide). At the edge of the cell, the opposite contact is of conventional heavily doped silicon. The edge contact is kept in the dark at least one diffusion length or one-third mm laterally displaced away from both the active illuminated region and from the active heterocontact.

Thin-film silicon and GaAs solar cells

Abstract: The growth of thin films of crystalline silicon and GaAs on inexpensive substrates offers the promise of combining the high performance of single crystal solar cells with the low cost of thin-film solar cells. The large number of potential crystal growth processes for achieving the desired structure can be organized into melt growth, vapor phase growth, solid state growth and solution growth. Solution growth offers several advantages for the development of solar cell quality material on dissimilar substrates. Thin solar cell design, the selection criteria that led to the choice of solution growth, a description of the growth stages and the growth of silicon on glass and steel and GaAs on aluminum are described.

Inversion layer solar cells on chemically vapor‐deposited polycrystalline silicon thin films

Abstract: It is demonstrated that the metal‐insulator‐semiconductor (MIS) inversion layer (IL) process is also suited to fabricating solar cells on fine‐grained polycrystalline silicon thin films prepared by low‐pressure chemical‐vapor deposition (LPCVD). Plasma enhanced silicon nitride was used as dielectric to create a highly conductive inversion layer at the silicon surface. As revealed by high frequency and quasistatic C‐V measurements, the insulator/semiconductor interface for fine‐grained LPCVD polycrystalline silicon is similar to that for the coarse‐grained Wacker Silso material. An excellent external quantum efficiency in the short wavelength region was obtained for solar cells on both materials. For the 1‐cm2 solar cell on 2‐Ω cm p‐doped LPCVD silicon an active area efficiency of ηa=1.8% was obtained. Ways of improving these cells are suggested. A total area AM1 efficiency of 13% was achieved for coprocessed 4‐cm2 MIS‐IL solar cells on Wacker Silso.

Lead-cadmium-sulphide solar cell

Abstract: A solar cell in which the essential feature is a thin film of lead-cadmium-sulphide alloy. This alloy is preferably formed by spray pyrolysis from a solution containing the necessary ingredients. The solar cell advantageously takes the form of a homojunction constructed of two layers of lead-cadmium-sulphide alloy, with one of the layers being p-doped and the other of the layers being n-doped. The solar cell may be produced with an intrinsic layer interposed between the p-type layer and the n-type layer. The solar cell may also be made with a semiconductive layer of lead-cadmium-sulphide in contact with a metallic substrate.

Structurally stable, thin silicon solar cells

Abstract: A modification, during the wafer-etching process for thin solar cells, provides the thin structure with silicon reinforcing ribs. The result is a lightweight solar cell with significantly increased fabrication yield.

Solar Cell Fabrication Techniques for Single and Semicrystalline Silicon Substrates

Abstract: Several technologies for silicon solar cell fabrication are reviewed. More specifically, the characteristics of a process line, based on the use of thick film technology, are discussed. The technology, using screen printing and heat treatments in a conveyor furnace, is attractive for junction formation, metallization and deposition of the antireflective coating. The process can be implemented on single crystalline, semicrystalline and thin film crystalline silicon films, deposited on cheap substrates. The add-on cost of this solar cell fabrication process is 2 to 2.5 $/W for a 270 kW/year production line and can be as low as 0.5 to 0.6 $/W for a 10 MW/year capacity fully automated cell factory.

PIN Amorphous silicon solar cell with nitrogen compensation

Abstract: A PIN amorphous silicon solar cell including a nitrogen compensated intrinsic inter-layer adjacent to the P type layer forming the light receiving face of the cell.

GaAs/Ge/Si solar cells

Abstract: Shallow-homojunction GaAs solar cells fabricated on Ge-coated Si substrates have achieved conversion efficiencies of 14 and 11% (AM1, one sun) for areas of about 0.093 and 0.51 cm/sup 2/, respectively. The electrical characteristics of the cells have been studied by quantum efficiency, junction diode factor and dark current measurements, and their structural properties by transmission electron microscopy and electron-beaminduced-current imaging. The effects of dislocations, which are the predominant defects in the GaAs layers, on solar cell performance are discussed. Recent advances in monolithic GaAs-Si tandem cells are also reported.