PROGRESS IN AMORPHOUS-SILICON PHOTOVOLTAIC-DEVICE RESEARCH

The authors have been studying the application of hydrogenated amorphous-silicon to solar cells for a number of years. They review here some of their results and progress since the First Canadian Semiconductor Technology Conference. These include, first, quantification of the dependence of film characteristics on the deposition parameters such as DC bias, Ar:SiH//4 ratio, temperature, and gas flow for the capacitive reactor geometry used; second, construction of a time-of-flight spectrometer permitting mass resolution of elastically scattered or recoiling nuclei and the chemical-composition profiling of multilayer device structures; third, electro-optical characterization of doped and undoped a-Si:H films; fourth, fabrication of 3-mm**2 MIS diodes having efficiencies of 5. 3% and short-circuit currents of 22 mA/cm**2; fifth, development of theoretical models for the behavior of Schottky structures; sixth, development of a new technique for doping a-Si:H by the controlled evaporation of group III or V metals into an rf plasma discharge of silane and argon; and finally, construction of p-i, n-i, and p-i-n solar cells using the novel doping procedure.