摘要:

The performance of a sparger‐type, singlet‐delta‐oxygen generator using various amines as alternative bases to NaOH was found to be comparable to the performance of a generator with the Cl2‐NaOH‐H2O2‐H2O reactant system. Based on the percentage of singlet‐oxygen evolution from the generator and the known rates of reaction between Cl2and propylamine, the reaction between Cl2and HO−2, which is assumed to produce singlet oxygen, is estimated to be ∼108M−1 s−1.

ISSN:0021-8979    

DOI:10.1063/1.331031

出版商:AIP    

年代:1982

数据来源: AIP

摘要:

Defects across the back‐surface‐field junction (BSF) can seriously degrade the performance of high‐efficiency solar cells. Poor alloying, diffusion pipes, random contact metal penetration, and impurity segregation and clustering can all cause partial or complete electrical short circuits across the BSF junction. Performance degradation from defects distributed in the bulk across the BSF junction is analyzed using the newdeveloped‐perimetermodel. A defective unit cell, containing one defect, is characterized by a three‐region developed‐perimeter device model. The width of the first region surrounding the defect is characterized by the range or the distance‐of‐influence of the defect and this range is shown to be about two diffusion lengths. The defect itself is characterized by three parameters: the defect area, the defect areal density, and the surface recombination velocity at the defective area. This defect model applies to both a few defects and a large number of defects. Family of curves and numerical examples are presented to show that there is very substantial degradation of open‐circuit voltage in thin and high‐efficiency cells, even if there are only a few defects. It is also shown that the degradation is not sensitive to the defect area but highly dependent on the defect density. Two defects of half area will cause almost twice as much open‐circuit‐voltage degradation than one defect of twice the area due to the two‐diffusion‐length defect range or distance‐of‐influence. Due to the strong density dependence, bulk defects, even at low density, could pose a serious limitation to the attainment of theoretical high open‐circuit voltage and efficiency in thin and high‐efficiency back‐surface‐field solar cells.

ISSN:0021-8979    

DOI:10.1063/1.331032

出版商:AIP    

年代:1982

数据来源: AIP

摘要:

This paper describes and analyzes a generalized approach to compression networks that uses both opening and closing switches. An efficiency of compression equation showing the dependence of efficiency on parasitic parameters is derived. This equation indicates that a unique geometric mean relationship has to be maintained and an optimum number of stages must exist for maximum energy compression.

ISSN:0021-8979    

DOI:10.1063/1.330983

出版商:AIP    

年代:1982

数据来源: AIP

摘要:

A new experimental method is presented here by which the density of water, glycerol, HIW (a mixture of isopropyl ammonium nitrate, hydroxyl ammonium nitrate, and water), and solithane 113 was measured at 25 °C and pressure up to 410 MPa.

ISSN:0021-8979    

DOI:10.1063/1.330984

出版商:AIP    

年代:1982

数据来源: AIP

摘要:

The aim of this paper is to present the first images obtained in scanning x‐ray radiography without the help of synchrotron radiation but simply with a classical x‐ray source, that is, a scannable electron beam focused on an aluminum foil to produce characteristic x‐ray lines. The emitted x rays (about 1011–1012x‐ray photons s−1 mm−2) allow the observation of highly absorbing specimens in a nonabsorbing matrix about 10 &mgr;m thick. We show that these results can be improved by simple modifications of a scanning transmission electron microscope.

ISSN:0021-8979    

DOI:10.1063/1.330985

出版商:AIP    

年代:1982

数据来源: AIP

摘要:

Oscillatory modes of the Pierce system have been calculated. These modes are found to have growth rates comparable to the previously investigated purely growing modes. When these modes are included, it is found that the Pierce system is unstable for most values of &ohgr;pL/V0≳&pgr;.

ISSN:0021-8979    

DOI:10.1063/1.330986

出版商:AIP    

年代:1982

数据来源: AIP

摘要:

The characteristic equation showing the dependence of the steady‐state current for point‐to‐plane electrical corona discharges on the point‐to‐plane potential and other relevant parameters is derived. The mathematical model is based on hyperboloid point to plane geometry and assumes a constant charge‐carrier mobility with a constant potential drop across the corona glow region. The equation is an exact relationship for this geometry in that no calculation approximations are used in its derivation.

ISSN:0021-8979    

DOI:10.1063/1.330987

出版商:AIP    

年代:1982

数据来源: AIP

摘要:

Field‐effect Hall mobility studies were made on polycrystallinen‐type InSb films. The intergrain barrier potential is found to be dependent on both temperature and applied gate field. The experimental results fit well with an intergrain barrier potential of the form &fgr;b= &fgr;0(1+&agr;T)(1+&agr;q+bq2), where &fgr;0is the value of &fgr;bat zero gate field and absolute zero temperature, &agr; is the temperature coefficient of &fgr;b, andaandbare constants.

ISSN:0021-8979    

DOI:10.1063/1.330988

出版商:AIP    

年代:1982

数据来源: AIP

摘要:

Deep levels in semi‐insulating GaAs:Cr have been detected and characterized before and after Si implantation and thermal annealing. The measurement techniques used were current transients, photoinduced current transients, capacitance transients, and photocapacitance transients. Hole emission from the Cr centers with activation energy &Dgr;ET= 0.85±0.01 eV was recorded in the semi‐insulating substrates as well as in the implanted layers. An electron trap level with &Dgr;ET= 0.52±0.01 eV and a hole trap with &Dgr;ET= 0.15±0.01 eV have been consistently observed in the implanted and annealed GaAs. The capture cross section of these traps and other traps detected in unimplanted and implanted GaAs:Cr have been determined.

ISSN:0021-8979    

DOI:10.1063/1.330989

出版商:AIP    

年代:1982

数据来源: AIP

摘要:

The bulk diffusion coefficient of aluminum in ion‐implanted paramagnetic iron‐aluminum alloys has been determined to have an activation energy of 3.17±0.15 eV and preexponential factor of 1.6±4.60.2cm2/s by measuring the time evolution of aluminum profiles in the temperature range 775–900 °C.

ISSN:0021-8979    

DOI:10.1063/1.330990

出版商:AIP    

年代:1982

数据来源: AIP