Properties of Bi-doped PbTe layers grown by liquid phase epitaxy under controlled Te vapor pressure |
| |
Authors: | Wataru Tamura Arata Yasuda Ken Suto Masasuke Hosokawa Osamu Itoh Jun-Ichi Nishizawa |
| |
Affiliation: | (1) Department of Materials Science, Faculty of Engineering, Tohoku University, Aramakiaza Aoba, 980-0845 Sendai, Japan;(2) Semiconductor Research Institute, Kawauchi Aoba, 980-0862 Sendai, Japan |
| |
Abstract: | Effects of Bi doping in PbTe liquid-phase epitaxial layers grown by the temperature difference method under controlled vapor
pressure (TDM-CVP) are investigated. For Bi concentrations in the solution, xBi, lower than 0.2 at.%, an excess deep-donor level (activation energy Ed≈0.03–0.04 eV) appears, and Hall mobility is low. In contrast, for xBi>0.2 at.%, Hall mobility becomes very high, while carrier concentration is in the range of 1017 cm−3. Inductive coupled plasma (ICP) emission analysis shows that, for xBi=1 at.%, Bi concentration in the epitaxial layer is as high as NBi=2.3–2.7 × 1019 cm−3. These results indicate that Bi behaves not only as a donor but also as an acceptor, and the nearest neighbor or very near
donor-acceptor (D-A) pairs are formed, so that strong self-compensation of Bi takes place. Carrier concentration for highly
Bi-doped layers shows a minimum at a Te vapor pressure of 2.2 × 10−5 torr for growth temperature 470°C, which is coincident with that of the undoped PbTe. |
| |
Keywords: | PbTe liquid phase epitaxy (LPE) Bi doping |
本文献已被 SpringerLink 等数据库收录! |
|