摘要:

This communication provides a detailed examination of the morphology of thin films of CuInSe2prepared by chemical spray pyrolysis on borosilicate glass, molybdenum‐coated glass, and CdS substrates. The latter two are used in thin‐film heterojunction solar cells of CuInSe2/CdS in the backwall and reverse backwall (RBW) configurations, respectively, and hence are of great technological interest. The pseudoepitaxial growth of CIS on CdS and its low deposition temperature (250 °C) which inhibits interdiffusion suggest that one should prepare CuInSe2/CdS solar cells in the RBW configuration.

ISSN:0021-8979    

DOI:10.1063/1.346494

出版商:AIP    

年代:1990

数据来源: AIP

摘要:

Interface traps and oxide charge generated by x ray and high‐field Fowler–Nordheim (FN) injection are monitored within the first hour after their creation. A characteristic interface‐trap peak distribution in the upper half of the Si band gap (∼Ev+0.75 eV) is invariably found immediately after x‐ray irradiation or gate‐positive FN injection. However, this peak distribution is not observed immediately after gate‐negative FN injection; instead, it gradually develops with time after the injection, and is accompanied by a gradual reduction of the positive oxide charge density. In contrast, the interface‐trap distribution after x ray or gate‐positive FN injection undergoes much less notable changes within the first hour. In addition, the amount of damage measured immediately after FN injection depends strongly on the injection polarity, with gate‐positive injection generating more interface traps and less positive charge while the reverse is true for gate‐negative injection. These observations may be explained in terms of the differences in the initial trapped hole distribution and subsequent electron‐hole interactions under different damage conditions.

ISSN:0021-8979    

DOI:10.1063/1.346471

出版商:AIP    

年代:1990

数据来源: AIP

摘要:

Tracer diffusion of110Ag in YBa2Cu3O7−&dgr;has been measured in the temperature range 800–950 °C using serial sectioning. The polycrystalline samples were made either from a powder containing about 0.2% Zr prepared by a conventional technique, or from a purer powder that had been calcined in low‐pressure oxygen. Concentration profiles indicate both a volume and a fast diffusivity path contribution to diffusion. The activation energies were 227±3 and 249±17 kJ/mole for samples made from powder calcined in low‐pressure oxygen and conventional powder, respectively. Diffusion was slower in the samples made from the purer powder.

ISSN:0021-8979    

DOI:10.1063/1.346472

出版商:AIP    

年代:1990

数据来源: AIP

摘要:

Nonexponential relaxations may be decomposed into a distribution of elementary exponential relaxations. Although of mathematical interest, these distributions may not have a physical sense if the elementary process of dipolar orientation itself is nonexponential, that is, non‐Debye. We analyze non‐Debye models using the superposition principle and assume that they admit a rate equation. In this case the rate itself results to be time dependent. Using the superposition principle as a guide, it then is possible to find the polarization for nonisothermal processes and even for time‐varying electric fields. We finally comment on defect diffusion models devised to explain the dynamics of the polarization and depolarization unit, which seem not to be in accord with the superposition principle.

ISSN:0021-8979    

DOI:10.1063/1.346473

出版商:AIP    

年代:1990

数据来源: AIP

摘要:

Fresh surfaces of polycrystalline Al‐49.2%Cu, Al, and In are fabricated in duffusion pump oil, and observedinsituusing a scanning tunneling microscope. The current images reflect the atomic arrays on their surfaces. More clear images with atomic resolution are observable about 10 h later compared with those just after the fabrication. Atomic resolution images are observable in oil several days after, with increasing noise.

ISSN:0021-8979    

DOI:10.1063/1.347174

出版商:AIP    

年代:1990

数据来源: AIP

摘要:

The characteristics of erbium implants in a silicon‐on‐insulator structure were studied by photoluminescence and electrical activation measurements. The results indicate that a correlation exists between the luminescence energy or the lattice configuration and the electrical activation of the erbium in the implanted materials. Meanwhile, this work suggests a new way to enhance the luminescence efficiency of the erbium implanted materials.

ISSN:0021-8979    

DOI:10.1063/1.346474

出版商:AIP    

年代:1990

数据来源: AIP

摘要:

For the first time, ZnSe epitaxial layers grown by molecular‐beam epitaxy are shown to exhibit large contrast, low power, and extremely long‐term stable thermally induced absorptive optical bistability. It is observed over a wide temperature range between 169 K and RT, with a strongly variable loop width and a switch‐back adjustable to be less than 50% of the respective switch‐down value. Critical slowing down as well as switch‐down times are studied in dependence of the excess over the switch‐down intensity values.

ISSN:0021-8979    

DOI:10.1063/1.346475

出版商:AIP    

年代:1990

数据来源: AIP

摘要:

Deep‐level defects in Li+‐implanted ZnSe epilayer grown by metalorganic vapor‐phase epitaxy (MOVPE) on a GaAs substrate have been characterized by using the deep‐level transient spectroscopy method under different post‐implantation annealing conditions. Four electron traps with energy levels ofEc−0.3, 0.33, 0.55, and 1.02 eV and one hole trap with an energy level ofEv+0.23 eV were detected. Possible physical origins and formation mechanisms for these defects were discussed using the defect model proposed by Myles and Sankey [Phys. Rev. B29, 6810 (1984)]. The results showed that interdiffusion between the ZnSe/GaAs heterointerface plays an important role on the formation of native defects in the MOVPE‐grown ZnSe epitaxial films on the GaAs substrate.

ISSN:0021-8979    

DOI:10.1063/1.346476

出版商:AIP    

年代:1990

数据来源: AIP

摘要:

Trimethylgallium (TMGa) heterogeneously decomposes predominantly at a lower partial pressure than 3×10−3atm in the presence of GaAs. As the TMGa partial pressure becomes larger, more TMGa decomposes in the gas phase than on the surface. The decomposition mechanism using the Langmuir adsorption isotherm is explained; the TMGa adsorbs on the surface obeying the Langmuir adsorption isotherm and TMGa decomposes on the surface as well as in the gas phase. From this decomposition mechanism the TMGa decomposition rate constant in H2without the surface catalysis is evaluated as lnkg(s−1) =38.8–57.6 (kcal/mol)/RT.

ISSN:0021-8979    

DOI:10.1063/1.346477

出版商:AIP    

年代:1990

数据来源: AIP

ISSN:0021-8979    

DOI:10.1063/1.347202

出版商:AIP    

年代:1990

数据来源: AIP