Effects of ion beam hydrogenation on silicon solar cell structures

A Kaufman ion source was used to hydrogenate polycrystalline silicon structures at energies from 250 to 5000 eV. This results in improvements in photovoltaic properties and in shorter hydrogenation times than have been reported by other groups using arc or plasma discharges. Single-crystal silicon samples exposed to similar hydrogenation conditions were evaluated using scanning electron microscopy. IR spectroscopy, reflectometry and ellipsometry. The thickness and other characteristics of this modified surface region vary as a function of the ion energy and the dose rate. The properties of this surface region may influence the choice of subsequent antireflective coatings that are used to provide optimum performance of these devices. (Auth.)