Energy distribution of trapping states at grain boundaries in polycrystalline silicon

A method to obtain the energy distribution of traps at grain boundaries in polycrystalline silicon films from the activation energy of resistivity measured as a function of doping concentration is proposed. The energy distribution of trapping states in the energy gap for plasma-hydrogenated and nonhydrogenated polycrystalline silicon films doped with boron are determined: nonhydrogenated films have a Gaussian distribution with a peak at the midgap, and after plasma hydrogenation the peak at the midgap has diminished. The validity of the monoenergetic trap model applied to the conduction in nonhydrogenated and plasma-hydrogenated polycrystalline silicon films is discussed.