节点文献
Mg acceptor activation mechanism and hole transport characteristics in highly Mg-doped AlGaN alloys
【摘要】 The Mg acceptor activation mechanism and hole transport characteristics in AlGaN alloy with Mg doping concentration(~ 1020 cm-3) grown by metal–organic chemical vapor deposition(MOCVD) are systematically studied through optical and electrical properties. Emission lines of shallow oxygen donors and(VⅢ complex)1- as well as VN3+ and neutral Mg acceptors are observed, which indicate that self-compensation is occurred in Mg-doped AlGaN at highly doping levels. The fitting of the temperature-dependent Hall effect data shows that the acceptor activation energy values in Mgdoped AlxGa1-xN(x = 0.23, 0.35) are 172 meV and 242 meV, and the hole concentrations at room temperature are 1.2×1018 cm-3 and 3.3× 1017 cm-3, respectively. Therefore, it is believed that there exists the combined effect of the Coulomb potentials of the dopants and screening of the Coulomb potentials by a high hole concentration. Moreover, due to the high ionized acceptors’ concentration and compensation ratio, the impurity conduction becomes more prominent and the valence band mobility drops sharply at low temperature.
【Abstract】 The Mg acceptor activation mechanism and hole transport characteristics in AlGaN alloy with Mg doping concentration(~ 1020 cm-3) grown by metal–organic chemical vapor deposition(MOCVD) are systematically studied through optical and electrical properties. Emission lines of shallow oxygen donors and(VⅢ complex)1- as well as VN3+ and neutral Mg acceptors are observed, which indicate that self-compensation is occurred in Mg-doped AlGaN at highly doping levels. The fitting of the temperature-dependent Hall effect data shows that the acceptor activation energy values in Mgdoped AlxGa1-xN(x = 0.23, 0.35) are 172 meV and 242 meV, and the hole concentrations at room temperature are 1.2×1018 cm-3 and 3.3× 1017 cm-3, respectively. Therefore, it is believed that there exists the combined effect of the Coulomb potentials of the dopants and screening of the Coulomb potentials by a high hole concentration. Moreover, due to the high ionized acceptors’ concentration and compensation ratio, the impurity conduction becomes more prominent and the valence band mobility drops sharply at low temperature.
【Key words】 AlGaN; Mg doping; MOCVD; cathodo-luminescence; Hall measurement;
- 【文献出处】 Chinese Physics B ,中国物理B , 编辑部邮箱 ,2020年05期
- 【分类号】TG146.21
- 【下载频次】17