Magnesium Doping Controlled Density and Mobility of Two-Dimensional Electron Gas in MgxZn^xO/ZnO Heterostructures

摘要

The magnesium content in MgxZn^xO/ZnO heterostructures grown by molecular beam epitaxy enables the careful control of the carrier density of the two-dimensional electron system down to 5.6 x 1010crrr2 while retaining a mobility of 200,000cm2 V"1 s~1 when pursuing magnesium concentrations as low as x = 0.0038. By selecting an optimum magnesium content (x~0.01), the mobility is enhanced to over 700,000 cm2 V"1 s~1 due to reduced impurity levels associated with the use of pure distilled ozone and avoiding interface roughness scattering. This control technique allows access to the coherent transport region with strong electron-electron interaction.