Abstract: An electrochromic arrangement particularly useful in a region of the infra-red spectrum above 3 microns comprises in order a rear glass substrate (1), a film electrode (2) with an IR reflectivity of at least 50%, an ion storage layer (3) an ion conducting layer (4). An electrochromic tungsten oxide layer (5) having at least a degree of crystallinity, a silicon front electrode (6) and an antireflection coating (7). In the uncharged state of layer (5) all layers (3-7) are transparent and most incident light is reflected at (2). On entering the charged state the layer (5) exhibits a marked increase in light absorptivity and refractive index. In a device incorporating a bare layer (5) the latter causes such a large increase in reflectivity at the front surface that the increase in light absorption tends to be masked, with a resulting increase in reflectivity of the device.

Abstract: A process is disclosed for removing heavy metals, dissolved aluminum, sulfides and organic compounds from a caustic etch solution, thereby regenerating the etching power of the solution or facilitating its disposal into the environment. The process consists of forming a first filtrate from which heavy metals present in the solution have been removed, and a second filtrate obtained by precipitating and oxidizing residual chemicals remaining in the first filtrate. The latter is done over a selected pH and temperature range. The second filtrate is then either reclaimed back to the etching tank, or subjected to ozonization prior to disposing of it into the environment.

Abstract: A process is disclosed for removing heavy metals, dissolved aluminum, sulfides and organic compounds from a caustic etch solution, thereby regenerating the etching power of the solution or facilitating its disposal into the environment. The process consists of forming a first filtrate from which heavy metals present in the solution have been removed, and a second filtrate obtained by precipitating and oxidizing residual chemicals remaining in the first filtrate. The latter is done over a selected pH and temperature range. The second filtrate is then either reclaimed back to the etching tank, or subjected to ozonization prior to disposing of it into the environment.

Abstract: Compact and versatile apparatus for deposition of multi-layer coatings on substrates at reduced pressure comprises at least 3 and preferably at least 4 evacuable deposition chambers, means for evacuating each of said deposition chambers and coating means in each of said deposition chambers for depositing a coating layer on a substrate; an evacuable transfer chamber with closable ports between said transfer chamber and each of said coating chambers for transfer of a substrate to be coated between said deposition chambers; means for evacuating said transfer chamber; and transfer means for transferring a substrate between said deposition chambers via the transfer chamber. The apparatus is especially useful for the production of photovoltaic cells in which the active layers are formed of amorphous silicon deposited from a glow discharge.