Showing papers on "Polymer solar cell published in 1986"

Enhancement of open circuit voltage in high efficiency amorphous silicon alloy solar cells

Abstract: We have developed a microcrystalline fluorinated p+ silicon alloy which has high dark conductivity and low optical loss. Incorporation of this material in single and tandem amorphous silicon alloy based solar cells has resulted in increased open circuit voltage and conversion efficiency.

Point Contact Silicon Solar Cells

Abstract: A new type of silicon concentrator solar cell has been developed. It is called the point-contact cell because the metal semiconductor contacts are restricted to an array of small points on the back of the cell. The point contact cell has recently demonstrated 22 percent conversion efficiency at one sun and 27.5 percent at 100 suns.

Thin film CdZnS/CuInSe2 solar cells by spray pyrolysis

Abstract: Cd1−xZnxS/CuInSe2 solar cells having efficiencies in the range of 2·3% were fabricated by spray pyrolysis. The best cell had the following parameters:V oc = 305 mV,J sc = 32 mA/cm2, FF = 0·32 area = 0·4 cm2 and efficiency = 3·149%.V oc versus temperature measurements showed that the electron affinity difference was 0·22 eV. Forward dark current versus voltage curves were plotted and a possible current mechanism occurring in these cells has been proposed.

Process for fabricating a 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.

Solar cells based on CuInS2

Abstract: Solar cells with photoanodes based on CuInS2 semiconductor material produced by specially adapted methods, permit the transformation of light into electric energy with a good efficiency. The semiconductor material according to the invention comprises inclusions of extraneous phases, namely In2 S3, In and/or Cu2-x S (0≦x≦1) in a concentration between 5 per thousand and 5 percent, in the CuInS2. The energy gap of this material is 1.5 eV. Working electrodes for photoelectrochemical solar cells or solid state solar cells can be constructed.

Status of Fluorinated Amorphous Silicon Alloy Multi-Junction Solar Cells

Abstract: We present in this paper updated solar cell performance data on fluorinated amorphous silicon and fluorinated amorphous silicon-germanium alloys. We have achieved a 9.7% conversion efficiency for a single-junction device using a-Si:Ge:F:H alloy having an optical band gap of 1.5 eV. We have also achieved 12.5% and 13.0% efficiencies, respectively, for dual-band-gap tandem and triple devices using a-Si:F:H and a-Si:Ge:F:H alloys. These represent the highest values reported to date for their respective configurations. Multi-junction solar cells exhibit excellent stability not only in terms of light-induced effect but also in terms of prolonged heating at elevated temperatures.

Process for producing hydrogenated amorphous silicon thin film and a solar cell

Abstract: The speed of forming a film of a hydrogenated amorphous silicon (a-Si:H) can be increased by controlling the amount of a supplied energy in relation to the film-forming speed. Application of this technique to the production of a solar cell enables a hydrogenated amorphous silicon solar cell (a-Si:H cell) having a high photoelectric conversion efficiency to be produced at high speeds. The aforesaid controlling procedure comprises adjusting the amount (KJ/g-Si2 H6) of an energy to be supplied to a film-forming speed depends mainly upon the flow rate of the gas and is not substantially affected by the amount of the energy.

Influence of Transparent Conducting Oxide on Amorphous Silicon Solar Cell Performance

Abstract: The use of transparent conducting oxides (TCO) as electrical contacts in a-Si:H solar cells has stimulated interest in the multitude of effects that these layers have on a-Si:H solar cell performance. The study of a-Si:H p-i-n junctions using a TCO contact involves many factors such as, interdiffusion, transmission, reflection, and resistivity. In this paper, we attempt to distinguish between these factors through the role they play in determining the solar cell device performance. Devices were characterized via dark and illuminated current vs. voltage (I-V) measurements, and spectral response. It was found that the properties of the TCO have an important role in influencing FF and Jsc in the devices.

Solar-grade silicon prepared by carbothermic reduction of silica

Abstract: An advanced carbothermic reduction (ACR) process was developed to produce solar grade (SC) silicon from high purity silica and carbon Preparation of starting materials and operation of the arc furnace to product high purity silicon is described Solar cells prepared from single crystal SG-Si had efficiencies of up to 123% practically identical to cells made from electronic grade silicon The ACR process is not in the pilot stage for further evaluation

Effect of doping concentration on the performance of large‐grain polycrystalline silicon solar cell

Abstract: A theoretical study of the influence of the doping concentration on the efficiency of large‐grain polycrystalline silicon solar cells is presented. For grain‐boundary states density between 1011 and 1013 cm−2, we find the maximum efficiency for typical semi‐infinite solar cells to occur at doping concentration in the range between 1 and 4×1016 cm−3.

Amorphous silicon: from promise to practice

Abstract: Extensive research in solar cells has provided the basic understanding of amorphous silicon that is enabling a variety of companies to utilize this material in a host of new products. A major advantage of amorphous over crystalline technology is the significantly reduced cost. The low cost of amorphous technology is such that some applications would not be economically feasible without it, such as the solar cells that power pocket calculators. The author discusses amorphous silicon materials technology and explores two applications that are considered more significant; high-powered solar cells, and the thin-film transistor arrays that drive the latest generation of liquid-crystal color television and graphics displays, electrophotographic drums, gas sensors, and image arrays.

Measurement of properties of the n layer in hydrogenated amorphous silicon solar cells

Abstract: By measuring flat‐band voltage as a function of light intensity it is possible to get information about the transport properties of an intact solar cell. We illustrate different kinds of behavior and show how these are related to solar cell performance.

High-Efficiency, Large-Area P + -N-N + Silicon Solar Cells

Abstract: The work reports the development of high-efficiency, large-area, preferentially current-generating p+-n-n+ silicon solar cells. The distinctive trait of the developed cells is their extremely high value of the short-circuit current density Jsc under AM1 conditions (100 mW/cm2 insolation). Two main factors had shaped the unique features of these large-area (17.2 cm2) cells. One of the factors is the peculiar impurity profile of the p+-n junction with a depth of xj = 0.15–0.25 μm, obtained through adequate technological means. The second factor is a novel, optimized front grid metallization pattern, which reduces the areal inhomogeneities typical of large-area devices. The combined action of these factors has reduced the coverage ratio to about 5.6% and confined the series resistance R S to 60–100 m Ω range. The conversion efficiency of cells exceeds 17%. The results of this work were obtained in industrial environment, not laboratory conditions. It is noteworthy that none of the usual refinements (double AR layer, textured surface, etc.) were used in the fabrication process. Thus, this work shows clearly that a simple, but adequately designed/processed large-area p+-n-n+ cell could possess parameters similar or even superior to those of sophisticated laboratory samples elaborated on small (2 × 2 cm) silicon chips.

Stability of Amorphous Silicon Solar Cells — New Tandem a-SiC/a-Si Solar Cell

Abstract: Basic technologies for solving problems in thermal and light-induced degradation have been developed. The tandem type a-SiC/a-Si solar cell with blocking layers exhibits excellent stability for both thermal and sun light conditions. An observable light-induced degradation is not seen in the cell performance after light exposure test of 2000 hours. Two instability modes, that is, thermal and light-induced degradation have been investigated. For thermal degradation, a blocking layer for preventing diffusion has been inserted between the back side metal electrode and a n-layer and another blocking layer has been introduced between the np tunnel junction. To prevent light-induced degradation, p-type a-SiC layer of the pin structure on the side of a glass substrate/SnO2 has been deposited at the temperature of 70°C. The highest efficiency is 9.0% at the present stage, but it is expected to be improved to more than 10%.

Development Of Flexible A-Sic/A-Si Heterojunction Solar Cells And Stable A-Sic/A-Si Tandem Cells With Blocking Barriers

Abstract: The research and development of amorphous silicon solar cells at Kanegafuchi Chemical Industry Co. Ltd.(Kaneka) are introduced. In 1981, a wide gap a-SiC and a-SiC/a-Si hetero-junction solar cells were developed through joint research with Osaka University. Then flexible amorphous solar cell utilized the a-SiC/a-Si cell were developed and industrialized for the consumer market in 1983. To reduce the cost, a large capacity of deposition system were developed and built at Sakamoto plant in 1985. As to the instability of a-Si solar cell, a new and stable tandem cell has been developed which shows noble stability under both sun light and thermal conditions.

Contact Resistance Measurement Technique For Amorphous Semiconductors

Abstract: A technique for measuring the electrical characteristics of contacts to doped hydrogenated amorphous silicon (a-Si:H) or other high-resistivity thin film semiconductors is developed. Experimental results for metal and conductive transparent oxide contacts to both n- and p-type a-Si:H are presented and the significance of these values to solar cell applications discussed.

Status Of Amorphous Silicon Solar Cells At Solarex

Abstract: The Solarex Thin Film Division started commercial production of amorphous silicon solar cells for consumer applications in February 1984. Since that time, Solarex has produced more than twenty different types of amorphous silicon solar modules with sizes varying from 0.5cm2 to 1000cm2. The modules contain from 2 to 30 cells connected in series by sequentially patterning the various layers in the solar-cell structure. Conversion efficiencies as high as 10.9% have been obtained with superlattice p layers in 1.16cm2 p-i-n and efficiencies up to 8.7% have been obtained in large area modules (active area = 864cm2).

Fabrication and characterization of titanium dioxide (TiO2)/selenium thin‐film solar cells

Abstract: Recently, Se-based low-cost thin-film solar cells have been developed, resulting in an improvement of the conversion efficiency over conventional Se photocells. Although these solar cells enable increasing the photocurrent increase by designing a thin Se layer, no considerations have been given for the open-circuit voltage. The TiO2/Se solar cell described in this paper uses n-type TiO2 with remarkable photoconductivity as a window material. In addition, it reduces the dark current and improves the open-circuit voltage by operating as an MIS (Metal-Insulator-Semiconductor) diode in the dark and as a pn junction under the light illumination. As a result, the open-circuit voltage has been improved, and a cell with a conversion efficiency of 5.0 percent (short-circuit current is 10.8 mA/cm2, open-circuit voltage 0.88 V, fill factor FF 0.53) under simulated AM 1.5 (100 mW/cm2) illumination has been realized. This is the highest efficiency reported to date for Se solar cells. Additionally, since the spectral response is close to the emission spectrum of fluorescent lights, the efficiency improves to 11 - 13 percent under fluorescent lights (500 lux). Furthermore, since these cells have advantages of high sensitivity in short wavelengths, good photocurrent-illumination characteristics and low dark current, applications not only for solar cells but for light sensors such as color sensors and power meters are also expected.