. The Bell System technical journal. Telecommunication; Electric engineering; Communication; Electronics; Science; Technology. HOLE CONCENTRATION AND POINT CONTACTS 487 Haynes' measurements may be fitted by an empirical equation of the following form: / = h\\ + ypa/m)\, (51) in which /o is the normal collector current flow for a given collector volt- age, / is the collector current flowing for the same collector voltage when the hole concentration is increased by pa , and Hq is the normal electron concentration. Values of h and 7 for four different formed phosphor- bronze collector points are
. The Bell System technical journal. Telecommunication; Electric engineering; Communication; Electronics; Science; Technology. HOLE CONCENTRATION AND POINT CONTACTS 487 Haynes' measurements may be fitted by an empirical equation of the following form: / = h\\ + ypa/m)\, (51) in which /o is the normal collector current flow for a given collector volt- age, / is the collector current flowing for the same collector voltage when the hole concentration is increased by pa , and Hq is the normal electron concentration. Values of h and 7 for four different formed phosphor- bronze collector points are given in Table IV. The collector bias is â20 volts in each case. It can be seen that the variations in 7 are much less than those in /q. It will be shown below that 7 is related to the intrinsic a of the point contact. COLLECTOR Vf, = -20 VOLTS. â * lb SWEEPING CURRENT Fig. 8.âExperimental arrangement used b}' J. R. Haynes to determine relation be- tween hole concentration and current to collector point biased with large voltage in re- verse direction. In Haynes' experiment, holes are attracted to the collector by the field produced by the electron current and diffusion plays a minor role. In contrast to the preceding examples, the terms involving the field F in Eqs. (21) and (22) are large and the diffusion terms represented by the concentration gradients are small. It follows from (21) and (22) that the ratio of electron to hole current density is then: in/ip = bn/p, (52) which is equal to the ratio of the electron and hole contributions to the conductivity. If n and p do not vary with position, the ratio is the same everywhere and equal to the ratio of total electron and hole currents, /â and Ip'. Inllp = inlip = hnl p. (53) The currents /â and /,, can also be related to the intrinsic a for the con- tact by use of an equation of the form: / = /âo + a/p, (54). Please note that these images are extracted from scanned page images that may have been digitally enhanced for
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