Free GaAs surfaces studied using a back-gated undoped GaAs/AlxGa1−xAs heterostructure

作     者：A. Kawaharazuka T. Saku C. A. Kikuchi Y. Horikoshi Y. Hirayama 

作者机构：NTT Basic Research Laboratories 3-1 Morinosato-Wakamiya Atsugi-shi Kanagawa 243-0198 Japan School of Science and Engineering Waseda University 3-4-1 Okubo Shinjuku-ku Tokyo 169-0072 Japan CREST Core Research for Evolutional Science and Technology 4-1-8 Honmachi Kawaguchi-shi Saitama 331-0012 Japan 

出 版 物：《Physical Review B》 (Phys. Rev. B Condens. Matter Mater. Phys.)

年 卷 期：2001年第63卷第24期

页      面：245309-245309页

核心收录：

学科分类：0808[工学-电气工程] 0809[工学-电子科学与技术（可授工学、理学学位）] 07[理学] 0805[工学-材料科学与工程（可授工学、理学学位）] 0702[理学-物理学] 

摘      要：We study the free GaAs surface by using a back-gated undoped GaAs/AlxGa1−xAs heterostructure. This structure is suitable in investigating the free GaAs surface since a two-dimensional electron gas is induced by the back-gate bias in the undoped heterostructure. We compare the channel depth dependence of the transport characteristics with two different models of the free GaAs. The “midgap pinning model assumes a constant surface Fermi level and an alternative approach called the “frozen surface model assumes a constant surface charge density. The experimental results indicate that the frozen surface model appropriately describes free GaAs surfaces at low temperatures although the midgap pinning model is widely accepted. This is because charges cannot be transferred to the free GaAs surface at low temperatures.