论文部分内容阅读
一、引言在由未掺杂的窄禁带材料(如GaAs)和掺杂的n型宽禁带材料(如GaAlAs)组成的选择掺杂突变异质结构中,电子将从GaAlAs转移到亲合能较大的GaAs中,出于异质结势垒的限制,将在界面附近约100薄层内形成的一个平行于界面的二维平面内自由运动,而在垂直于界面的方向是受约束(能量量子化)的二维电子系统,即二维电子气(2DEG)。由于2DEG与其离化施主母体在空间上是分离的,因而可减少离化杂质散射,提高电子迁移率μ_n,特别是在低温下,晶格振动也大为减
I. INTRODUCTION In selective doping mutagenic heterostructures composed of undoped narrow bandgap materials (such as GaAs) and doped n-type wide bandgap materials (such as GaAlAs), electrons will be transferred from GaAlAs to the affinity In larger GaAs, due to the confinement of the heterojunction barrier, a two-dimensional plane parallel to the interface formed in a thin layer of about 100 "near the interface is free to move and is perpendicular to the interface Constraints (energy quantization) of the two-dimensional electronic system, that is, two-dimensional electron gas (2DEG). Since 2DEG is spatially separated from its ionized donor matrix, scattering of ionized impurities can be reduced and the electron mobility μ_n can be increased, especially at low temperatures, the lattice vibrations are greatly reduced