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Lazarus, David Craford, Magnus George 2011-07-08T16:02:36Z 2011-07-08T16:02:36Z 10000-01-01 1967 The pressure dependence of the electrical resistivity of n-type GaAs l -x Px is measured to a pressure of 7 kilobars at temperatures of 770, 195 0 , and 300 0 K. The samples are doped with sulfur and tellurium and have carrier concentrations in the 10^18 - 10^19 range. Changes in the resistivity as large as four orders of magnitude are observed at 77 0K for samples in the composition range 0.30 ~ x ~ 0.4~ The behavior of the samples is consistent with a model in which the higher lying [lOOJ conduction band edge has associated with it a donor level which is deep with respect to the [lOOJ minima. The level depth with respect to these minima is found to be 0.03 eV for Te-doped crystals, and ~ 0.06 eV for S-doped crystals. The S-doped samples also exhibit a light-sensitive, longlifetime trapping behavior. The trapping appears to be associated with an additional deep level which moves away from the [OOOJ conduction band minimum at the ratJ of approximately 10.8 x 10-3 eV/kbar. The data indicate that this trapping level is probably a second split-off level associated with and - 0.16 eV below the The mobility ratio of the two bands [equation] is found to be 15-30 at 3000K and 1950K but is found to increase to 60-100 at 77 0 K. The phosphorus concentration x at which the [OOOJ and [lOOJ minima are equal in energy appears to be x ~ 0.43 at 77 0K and x ~ 0.45 at 3000 K, implying that the separation between the minima increases with temperature at the rate of ~ 6 x 10-5 eV/oK. It is verified by combining resistance vs. pressure curves for samples of different composition x that increasing the pressure and increasing x have a similar effect on the band structure of the GaAs1-xPx system. Submitted by Carolyn Mead (cmead2@illinois.edu) on 2011-07-08T16:02:36Z No. of bitstreams: 1 1967_craford.pdf: 2953349 bytes, checksum: 7fa3ec4a7313910817be55b9fe022341 (MD5) Made available in DSpace on 2011-07-08T16:02:36Z (GMT). No. of bitstreams: 1 1967_craford.pdf: 2953349 bytes, checksum: 7fa3ec4a7313910817be55b9fe022341 (MD5) Previous issue date: 1967 Item marked as restricted to the 'UIUC Users [automated]' Group (id=2) by Carolyn Mead (cmead2@illinois.edu) on 2011-07-08T16:02:36Z Item is restricted indefinitely. Restriction data tranferred 2014-07-01T11:32:46-05:00 Original Data Group with Access UIUC Users [automated] Release Date: none Reason: Thesis Thesis U of I Only 2609778 http://hdl.handle.net/2142/25717 en 1967 Magnus George Craford electrical resistivity n-doped s-doped The effect of high pressure on S and Te-doped GaAs1-xPx Dissertation / Thesis text Physics Physics University of Illinois at Urbana-Champaign Dissertation Ph.D.