The electronic spectrum and electrical properties of germanium with a doubly charged gold impurity on both sides of the L-1 reversible arrow Delta(1)intervalley transition for uniform pressures of up to 7 GPa

The dependences of resistivity rho and the Hall coefficient R < 0 on hydros tatic pressure P (P less than or equal to 7 GPa) were studied at room tempe rature in Ge:(Au, Sb) with a partially populated (at 0 K) doubly charged Au level E-Au(2-) on both sides of the intervalley transition that occurred f or P congruent to 2.8 GPa. In terms of the two-band model, the baric depend ences rho (P) and R(P) and also the similar dependence of the Hall mobility with allowance made for interband scattering were calculated; the results agree satisfactorily with the experimental data. Characteristic parameters of the charge carriers and the baric coefficients for energy gaps between t he edges of the L-1 and Delta (1) subbands in the conduction band and the E -Au(2-) level were determined. It was ascertained that the position of the energy level for a doubly charged gold impurity in germanium is fixed with respect to the valence-band top. The density-of-state effective mass of ele ctrons in the (100) minimum of the conduction band of germanium was determi ned experimentally (and using the known values of the band parameters) and was found to be m(d Delta) = 6(2/3)(m(parallel to)m(perpendicular to)(2))(1 /3) = 1.05m(0). It is shown that Ge:Au2- can be used to check the uniformit y of pressure of up to 10 GPa. (C) 2001 MAIK "Nauka/Interperiodica".