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The detailed study of electrical properties in group III impurity doped ZnO thin films prepared by rf magnetron sputtering is described. The resistivity is lowered by doping of B, Al, Ga and In into ZnO films. The characteristic features of ZnO films doped with group III elements except for B are their high carrier concentration and low mobility. Variation of the mobility with the impurity content is roughly governed by the ionized impurity scattering. It is shown that the doped ZnO films exhibit the resistivity dependence on film thickness below 300 nm.

Highly transparent and conductive zinc-stannate thin films, ZnSnO3, have been prepared by rf magnetron sputtering using a target composed of ZnO–SnO2 ( SnO2, 78 wt%). A resistivity as low as 4×10-3 Ω·cm and an average transmittance above 80% in the visible range were obtained for undoped zinc-stannate films deposited with substrate temperatures ranging from room temperature to 300°C. The zinc-stannate films were relatively more stable in an oxidizing environment at high temperatures than either ZnO or SnO2 films. In addition, thermal stability in a hydrogen environment was improved over SnO2 films, and chemical stability in both acidic and basic solutions was improved over ZnO films.

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The proportion of each SC subtype was significantly associated with certain clinicopathological factors, suggesting different properties of each SC subtypes.

Highly transparent and conductive amorphous zinc-stannate thin films were prepared by rf magnetron sputtering using a target with a Zn/(Zn+Sn) content of 33 at. %. The resistivity distribution of the zinc-stannate films having a composition near ZnSnO3 and deposited on the surface of substrates placed parallel to the target surface was successfully controlled by optimizing both the sputter gas pressure and oxygen partial pressure. A uniform distribution with a resistivity of 4–5×10−3 Ω cm and an average transmittance above 80% in the visible range was obtained for undoped zinc-stannate films deposited on substrates from room temperature to 300 °C. The zinc-stannate films were found to be thermally and chemically more stable than undoped SnO2 and ZnO films.

Hole traps in p-type Cu 2 O were studied by means of deep level transient spectroscopy in the heterostructure of p-Cu 2 O/i-ZnO/ n-ZnO. In addition to the trap level at about 0.45 eV from the valance band edge, which is already reported as being due to Cu vacancy, we found a new trap level at about 0.25 eV. The new trap is tentatively assigned as Cu-di-vacancy from the trap concentration dependence on oxygen flow rate and substrate temperature. © 2006 American Institute of Physics. ͓DOI: 10.1063/1.2175492͔ Cuprous oxide ͑Cu 2 O͒, a direct band gap semiconductor with a band gap energy of 2.0 eV, has been regarded as one of the most promising materials for application to photovoltaic cells, 1,2 especially for the top cell in a tandem structure. The attractiveness of Cu 2 O as a photovoltaic material lies in the fact that the constituent materials are nontoxic, low cost and abundantly available. Cu 2 O / ZnO heterojunction has been fabricated by radio frequency ͑rf͒ magnetron sputtering and showed the photovoltaic effects, but did not demonstrate good performance. 3 Knowledge of defect energies as well as their densities is an important input for further improvement of the performance of Cu 2 O thin film polycrystalline solar cells. There are several reports on the deep trap in Cu 2 O by measuring deep level transient spectroscopy ͑DLTS͒. 4-6 A hole trap with the activation energy of about 0.45 eV from the valence band edge has been observed and assigned as Cu vacancy using Schottky diodes. However, the temperature range in the DLTS measurements was too narrow. It is necessary to measure the DLTS in the expanded temperature range in order to understand the origin of the defect in Cu 2 O. In this work, the DLTS spectra of Cu 2 O with the junction of n-ZnO/ i-ZnO/ p-Cu 2 O structure in the temperature range between 100 and 350 K is reported. We observed a new trap with the activation energy of 0.25 eV from the valence band edge in addition to the 0.45 eV trap, and the origin of the 0.25 eV trap is discussed based on the sample preparation conditions.Polycrystalline p-Cu 2 O/n-ZnO heterostructure was grown by means of rf magnetron sputtering on Corning 7059 glass substrate using a Cu target of 99.99% purity, ZnO target and Ar as sputtering gas. Oxygen was introduced during the growth of Cu 2 O through a nozzle whose end was placed near the substrate. We prepared two sets of samples for Cu 2

1IgG4 reactions consisting of marked infiltration by immunoglobulin G4 (IgG4)-positive plasma cells in affected organs is found in cancer patients as well as patients with IgG4-related diseases. Notably, extrahepatic cholangiocarcinomas accompanying marked IgG4 reactions clinicopathologically mimic IgG4-related sclerosing cholangitis. The regulatory cytokine interleukin (IL)-10 is thought to induce the differentiation of IgG4-positive cells. In this study, to clarify the mechanism of the IgG4 reaction in extrahepatic cholangiocarcinoma, we investigated nonprofessional antigen-presenting cells (APCs) generating IL-10-producing regulatory T cells (anergy T cells) and Foxp3-positive regulatory cells producing IL-10. Immunohistochemistry targeting IgG4, HLA-DR, CD80, CD86, and Foxp3 was performed using 54 cholangiocarcinoma specimens from 24 patients with gallbladder cancer, 22 patients with common bile duct cancer, and eight patients with cancer of the Papilla of Vater. Moreover, a molecular analysis of Foxp3 and IL-10 was performed using a cultured human cholangiocarcinoma cell line. Consequently, 43% of the cholangiocarcinomas were found to be abundant in IgG4. Those expressing HLA-DR but lacking costimulatory molecules (CD80 and CD86) and those expressing Foxp3 detected by an antibody recognizing the N terminus accounted for 54% and 39% of cases, respectively. Moreover, the number of IgG4-positive cells was larger in these cases than in other groups. In cultured cells, the presence of a splicing variant of Foxp3 messenger RNA and the expression of IL-10 were demonstrated. Conclusion: Extrahepatic cholangiocarcinoma is often accompanied by significant infiltration of IgG4-positive cells. Cholangiocarcinoma cells could play the role of nonprofessional APCs and Foxp3-positive regulatory cells, inducing IgG4 reactions via the production of IL-10 indirectly and directly, respectively. (HEPATOLOGY 2012;56:157-164) B iliary tract cancers can be anatomically divided into intrahepatic and extrahepatic cholangiocarcinomas, the latter including hepatic hilar cancer, common bile duct cancer, gallbladder cancer, and cancer of the Papilla of Vater. The biological behavior and carcinogenesis of each cancer differ, but the histology of most biliary tract cancers is the same as that of ordinary adenocarcinomas. In addition to neoplastic lesions, several types of cholangitis causing biliary stenosis are important in the differential diagnosis of biliary diseases. Particularly, primary sclerosing cholangitis and a complication of immunoglobulin G4 (IgG4)-related systemic diseases, IgG4-related sclerosing cholangitis, clinicopathologically mimic extrahepatic cholangiocarcinomas.IgG4 is a minor immunoglobulin subtype composing 3%-6% of all the IgG circulating in adults, 1 but is important for a systemic disorder, IgG4-related disease, that features elevated serum IgG4 levels and abundant