Accession Number : AD0621411

Title :   PRESSURE DEPENDENCE OF PHONON ASSISTED INTERBAND TUNNELING,

Corporate Author : CHICAGO UNIV ILL INST FOR THE STUDY OF METALS

Personal Author(s) : Fritzsche,H. ; Tiemann,J. J.

Report Date : 1964

Pagination or Media Count : 6

Abstract : Since very much is known about the band structure of germanium and of its dependence on stress, one can expect to obtain detailed information about the interband tunneling process by studying the effect of stress on the tunneling characteristics. Some structure has been briefly noted in the bias dependence of the relative change of tunneling current with hydrostatic pressure, in Sb-doped germanium tunnel junctions at 4.2 K. This effect is re-examined and it is shown that it cannot be explained by the Keldysh-Kane theory. Tunneling in germanium between states near the top of the valence band at the zone center and near the bottom of the conduction band at k = pi/a (1,1,1) can only occur if the difference in crystal momenta is supplied either by an interaction of the electron with an impurity or by a simultaneous emission or absorption of a (1 1 1) BZ edge phonon. Investigation was restricted to Sb-doped germanium for which the central cell potential of the impurities is so weak that the impurity-induced tunneling can be neglected. At helium temperatures, only phonon emission processes have to be considered. As a consequence the I-V curves show the characteristic phonon structure at the threshold voltages V = h omega/2epi and the contributions to the tunneling current of the TA, LA, LO and TO (1 1 1) phonons can easily be separated. (Author)

Descriptors :   (*TUNNELING(ELECTRONICS), PHONONS), (*STRESSES, TUNNELING(ELECTRONICS)), HYDROSTATIC PRESSURE, CRYSTAL LATTICES, GERMANIUM, ANTIMONY, CRYOGENICS

Distribution Statement : APPROVED FOR PUBLIC RELEASE