電子照射によるゲルマニウムの電気伝導度の変化

抄録

Effects of 1 MeV electron bombardment on conductivity of thin germanium single crystals originally about 10 ohm-cm n-type, 2 ohm-cm p-type and 40 ohm-cm undoped are studied. The observed initial carrier removal rates were 0.086 cm^-1 for n-type at 215°K, 0.15cm^-1 at 115°K and 0.051cm^-1 for p-type at 210°K. For undoped germanium, an increment of carriers was observed. If referred to hole, 0.003cm^-1 was obtained as the rate at 210°K which agrees with the rate of introduction of holes in n-type sample.
From the rates of carrier removal or introduction per displacement which was calculated by using the model of SEITZ and KOEHLER, the energy level scheme is estimated as following: an electron trap, 0.12 eV below conduction band obtained at 215°K, but 0.062 eV was obtained at 115°K; an acceptor, 0.28 eV above valence band at 210°K; a hole trap, 0. 073 eV above valence band at 210°K.