Abstract: A reduction gear including: a worm wheel, the tooth skin portion of which is at least made of macromolecular composite material, and a worm for meshing with the worm wheel concerned, wherein a tooth surface of the worm has been heat-treated by high-frequency induction hardening.

Abstract: A solar module made by the sequential stacking of a conducting metal oxide layer, an amorphous semiconductor layer, a back metal electrode, and a passivating resin layer on a transparent substrate, in which the passivating resin layer includes a water vapor barrier layer having a permeability to water vapor of not more than 1 g/m.sup.2 day measured at a thickness of 100 .mu.m, with the water vapor barrier layer being a polymer having a backbone consisting essentially of carbon and hydrogen. This barrier layer prevents the oxidation of the back metal electrode by water vapor, so that the stability of the module is improved in outdoor use.

Abstract: An integrated solar cell device characterized in that a plurality of amorphous silicon solar cells, each having a transparent electrode on the light impinging side and a metal electrode on the side opposite of the light impinging side, are placed on a transparent substrate. The plurality of solar cells are connected in series or series-parallel using the transparent electrodes and the metal electrodes thereof, wherein at least a conductive anti-oxidation film is formed at the series connection part between the transparent electrode and the metal electrode. According to the integrated solar cell device of the present invention, the transparent electrode is prevented from oxidizing the metal electrode, so that the contact resistance is prevented from increasing and the output of the solar cell device can be prevented from decreasing. Consequently, the life of the solar cell device is extended, such that the output of the solar cell device can be maintained in the designed range for a long period.