Study of potential high band-gap photovoltaic materials for a two step photon intermediate technique in fission energy conversion. Progress report for year one, December 1, 1990--November 30, 1991

摘要

A diamond synthesis chamber and an ion implanter have been constructed. Work has been rapidly progressing and diamond has been synthesized. There are five variables which affect the quality of diamond: (1) mass flow of methane, (2) mass flow of hydrogen, (3) filament temperature, (4) substrate temperature, and (5) substrate material. Enclosed are pictures and data of previous diamond growth experiments. Current work is focused on the conditions which produce the best quality diamond films. In this study, diamond films were deposited using a hot-filament CVD method with boron trioxide (B(sub 2)O(sub 3)) and diphosphorus pentoxide (P(sub 2)O(sub 5)) as the doping sources. P(sub 2)O(sub 5) is the only known effective phosphorus source for forming n-type semiconducting material. An RF generator has been made operation for epitaxial growth of AIN by the chemical vapor deposition method. In initial experiments with a graphite substrate, the RF generator heated the material to a temperature of 1100(degrees)C. A reactor which will use the RF generator has been built for AIN synthesis. The device should be assembled and tested by the end of August. A new process for fabricating platinum silicide photovoltaic cells has been developed. A diffused guard ring has been added to minimize leakage current. VUV to near IR capability has been developed for optical characterization. A microwave driven excimer lamp has been built and tested. Our previous work used a microwave source on an electron cyclotron heated ion source.