p型ゲルマニウムの小数キャリヤライフタイムに及ぼすγ線照射の影響

Mesurements of carrier lifetime from 150 to 300゜K have been made on samples of indiumand gallium-doped germanium after gamma irradiation at room temperature. In galliumdoped crystals, the formation of traps was observed only in a low resistivity material. The positions of the trapping levels were found to be O.66 eV and O.13 eV from the conduction band. It seems that the deep trap exhibits multiple trapping. The shallow trap was annealed readily at the stage around 430゜K but the deep trap was stable by annealing at this temperature. No trapping level was introduced by the irradiation into indium-doped sample.