Threshold Energy for Electron-Hole Pair-Production by Electrons in Silicon

Measurements have been made of the reverse bias required for the onset of multiplication in silicon $p-n$ junctions of various widths. A value of 2.25±0.10 ev is arrived at for the threshold energy for electron-hole pair-production by energetic electrons. There is apparently a slight variation of the threshold energy with crystallographic direction; the directions [100], [110], [111], are listed in ascending order of threshold energies. The ionization rate for electrons is greater than for holes.