摘要 |
<p>Amorphous semiconductors produced to form a wide variety of semiconductor devices, including photovoltaic devices suitable for solar energy conversion. Films produced by the invention have higher relative quantum efficiencies and sensitivities extending to a greater range of wavelengths than films of the prior art. According to the process of the invention, reactants, including the selected polysilanes, are applied to a reaction chamber (260) in the form of an envelope (261). The reaction chamber (260) contains a substrate (262) upon which amorphous silicon is to be deposited. The reaction chamber (261) has an inlet (263) and an outlet (264). The inlet provides entry for selected polysilanes or a monosilane-polysilane mixture through a control valve (251) which allows the gaseous mixture to be supplemented by one of more dopant gases from sources (252) and (255). Positioned below the inlet (263) is a support (265) for a holder (266) of the substrate (262). The substrate holder (266) is a cartridge heater with a wound ceramic core and a ceramic binder encompassing a resistive element (266r). A manometer (270) is mounted on the chamber (261) to give an indication of the internal pressure. The temperature of the substrate (262) is monitored by a gauge (not shown) included in the wiring for the heater (266r). The substrate (262) is typically of glass. In order to make the desired amorphous silicon deposit, the gaseous mixture G is passed over the substrate, being drawn toward the outlet (264) by the effect of a vacuum pump (not shown). The substrate (262) is operated at a temperature in the range from about 350`C. to about 500`C. resulting in pyrolytic decomposition of at least a portion of the gaseous stream G. The decomposition components are indicated by the arrows B shown in dashed line form. The balance of the gaseous mixture, in the form of an exhaust E is drawn through the outlet (264).</p> |