Metal-insulator transition in the compensated semiconductor Si:(P,B)
| Autor: | D. F. Holcomb, U. Thomanschefsky |
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| Rok vydání: | 1992 |
| Předmět: | |
| Zdroj: | Physical Review B. 45:13356-13362 |
| ISSN: | 1095-3795 0163-1829 |
| DOI: | 10.1103/physrevb.45.13356 |
| Popis: | The results of a continuing investigation of the effects of impurity compensation on the characteristics of the metal-insulator (M-I) transition in Si:P are reported. The system used is Si:(P,B). Most of the information is derived from measurements and analysis of the dc electrical conductivity \ensuremath{\sigma} in the temperature range 50 mK T4 K. The form of the temperature dependence of \ensuremath{\sigma} in this range is extensively studied. For samples with electron concentration n near ${\mathit{n}}_{\mathit{c}}$, the critical concentration for the M-I transition, the temperature dependence of \ensuremath{\sigma} departs significantly from the form \ensuremath{\sigma}=\ensuremath{\sigma}(0)+${\mathit{mT}}^{1/2}$+${\mathit{BT}}^{3/4}$, which describes samples at higher values of n. As K, the ratio of acceptor to donor concentration, is increased from zero, the value of ${\mathit{n}}_{\mathit{c}}$ first decreases slightly before rising sharply at larger values of K. Measurements of \ensuremath{\sigma}(0) as a function of n in uncompensated Si:P agree with data in the literature. The applicability of the scaling theory to a description of our measurements of \ensuremath{\sigma}(0) as a function of n in compensated samples is questioned. Attention is given to establishing the most reliable methods for determining values of impurity concentrations. |
| Databáze: | OpenAIRE |
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