摘要:

A survey of the potential of solar energy as a viable alternative for fossil fuels is presented. The present status of the six classes of solar energy conversion systems— (1) heating and cooling of buildings, (2) solar‐thermal electric power, (3) photovoltaic power, (4) ocean thermal‐gradient power, (5) bioconversion, and (6) wind energy conversion—is discussed and projections of energy costs are presented for each of these areas of development. (AIP)

ISSN:0022-5355    

DOI:10.1116/1.568470

出版商:American Vacuum Society    

年代:1975

数据来源: AIP

摘要:

The feasibility of silicon solar cells for large scale energy conversion is examined. In this context the availability of silicon and the cost of fabrication of devices are discussed. It is proposed that a complete rethinking of solar array processing is necessary to achieve large reduction in production costs. (AIP)

ISSN:0022-5355    

DOI:10.1116/1.568471

出版商:American Vacuum Society    

年代:1975

数据来源: AIP

摘要:

GaAs photovoltaic device structure are examined as an attractive alternate to Si devices for large scale terrestrial power generation. The role of other III‐V and II‐VI compounds, particularly CdS, is also discussed. (AIP)

ISSN:0022-5355    

DOI:10.1116/1.568711

出版商:American Vacuum Society    

年代:1975

数据来源: AIP

摘要:

Several ways that selective coatings can be used to enhance the performance of solar energy collection systems are reviewed. Coatings discussed include vacuum‐deposited, electroplated, and paint‐type selective solar absorber coatings and vacuum‐deposited and chemically etched antireflection and infrared reflecting coatings for glass. The optical and physical requirements for the coatings, as well as their effectiveness at increasing solar collector performance, are discussed.

ISSN:0022-5355    

DOI:10.1116/1.568712

出版商:American Vacuum Society    

年代:1975

数据来源: AIP

摘要:

An optical coating applied to a surface can cause radiation incident on the surface to be divided into transmission, reflection, and absorption in a prescribed manner. Thus, coatings affect the control of radiation and enhance the collection, conversion, and conservation of solar energy.

ISSN:0022-5355    

DOI:10.1116/1.568713

出版商:American Vacuum Society    

年代:1975

数据来源: AIP

摘要:

The application of materials to the thermal control of structures, photothermal/electrical conversion, and photovoltaic conversion are reviewed. Applications include solar and infrared reflectors, optical filters, transparent conductors, bulk semiconductor materials, semiconductor films, and selective solar absorbers. The use of thin films in many conservation and photothermal applications is presently economical, but the economics of photothermal/electrical and photovoltaic conversion is still being investigated. The means of obtaining selective solar absorbers which have a high solar absorptance and low ir emittance are discussed, and specific data on an electrodeposited black‐chrome selective absorber is presented. It is shown that solar–electric generating plants must be constructed at a cost of about $50/m2to be competitive with other electrical generating plants, and that a meaningful impact on the electrical energy economy will require a fabrication rate of greater than 1.8 × 108m2(50 square miles) per year. Present high‐volume deposition capabilities are reviewed, and it is shown that for some types of deposition, namely electrodeposition,e‐beam vacuum evaporation, and possibly sputter deposition, facilities exist which approach the desired volumes.

ISSN:0022-5355    

DOI:10.1116/1.568714

出版商:American Vacuum Society    

年代:1975

数据来源: AIP

摘要:

The concentration of sunlight offers distinct advantages for solar–electrical generation either by thermal conversion or by photovoltaics. A large variety of concentration techniques are available with concentration ratios of 1–1000. Concentration is required for thermal conversion systems to attain the high temperatures needed for efficiencies in the desired range of about 25%–35%. The projected costs for some of the solar thermal systems (especially the central receiver and the fixed mirror) indicate that they could be economically competitive in the southwestern states. The southwest may be required for these high‐concentration systems to overcome the main disadvantage of concentration, which is the use of the direct component of sunlight only. Other concerns of high‐intensity systems are in tracking requirements, reflective surface accuracy, and material lifetimes of both the reflecting and absorbing components. Selective surface absorbers will be required for systems with concentration ratios below a few hundred. The present high cost of solar‐cell‐generated electricity can be reduced considerably by using concentrators. Cells can be used with any of the concentrator designs, and the major concern is keeping them at acceptable operating temperatures. Planar silicon cells, vertical multijunction, and gallium–aluminum–arsenide cells all look attractive for concentrating systems.

ISSN:0022-5355    

DOI:10.1116/1.568715

出版商:American Vacuum Society    

年代:1975

数据来源: AIP

摘要:

Auger electron spectroscopic techniques were used to monitor the surface composition of a beryllium–copper alloy upon heating and oxidation to determine the surface composition necessary for maximum secondary‐electron yield. A 500–1000 Å BeO layer on the surface was found to give rise to the maximum secondary‐electron yield. Surface morphology was also found to play an important role. A wide range of oxygen pressures was found to produce the same surface condition and this fact was used in regeneration studies of fatigued Be–Cu electron multipliers.

ISSN:0022-5355    

DOI:10.1116/1.568716

出版商:American Vacuum Society    

年代:1975

数据来源: AIP

摘要:

Soft x‐ray appearance potential spectra of the 3dand 4dlevels of polycrystalline cerium metal are reported in this paper. Resonant x‐ray emissions are observed when the electron‐excitation energy sweeps through the ionization energies of the 3dand 4dlevels. The resonant x rays excited at the 3d‐level onsets are considerably more intense, and are excited at a lower electron‐excitation energy than the 3d‐series characteristic x rays. In the neighborhood of the 4d‐electron thresholds, four line‐like structures extend to ∠8 eV below the 4d‐electron binding energies, while two broad and more intense structures occur above the 4donsets, with the largest one reaching a peak intensity at 12 eV above the 4dthresholds. The resonant emissions apparently arise from the decay of threshold‐excited states which are bound to the inner vacancy and have core configurationsnd94f3, (n=3,4). The exchange interaction between the three 4felectrons and the respectived‐orbital vacancy spreads the 4d‐threshold structures over a 20 eV range of excitation energies and the 3d‐threshold structures over a much smaller range.

ISSN:0022-5355    

DOI:10.1116/1.568460

出版商:American Vacuum Society    

年代:1975

数据来源: AIP

摘要:

Radio‐frequency sputtering with rf‐induced substrate bias has been shown to be extremely valuable in tailoring the properties of many thin films. The use of this process has been inhibited by the lack of availability of simple equipment to implement it. We have designed a system which (1) is very rugged and reliable; (2) has no sensitive or critical tuning controls; (3) is insensitive to phase relationships; (4) is insensitive to fluctuations in gas discharge impedance; (5) is extremely stable, reproducible, and repeatable for long periods of time under a variety of sputtering conditions; and (6) can be operated, literally, in ’’push‐button’’ fashion.

ISSN:0022-5355    

DOI:10.1116/1.568461

出版商:American Vacuum Society    

年代:1975

数据来源: AIP