Effect of polarization roughness scattering (PRS) on two-dimensional electron transport of MgZnO/ZnO heterostructures

• For MgZnO/ZnO heterostructures, a new theoretical model of PRS is proposed.
• With PRS, the low-temperature electron transportation can be well explained.
• Effect of PRS on two-dimensional electron transport is calculated.
• Three-fold role of the polarization charge is presented.

Quantum transport properties of two-dimensional electron gas (2DEG) in undoped MgZnO/ZnO heterostructures with polarization charge effect have been investigated theoretically. Polarization roughness scattering (PRS) combining polarization charge and interface roughness scattering was proposed as a new scattering mechanism. It was found that the carriers confined in the heterostructures (HSs) would be scattered from polarization charges when they were moving along the in-plane and PRS played a very important role for the low-temperature electron mobility when the electron density Ns exceeded 1.0e11 cm−2, especially in a higher electron density region. With PRS, the experimental data on the density dependence of 2DEG mobility in the MgZnO/ZnO HSs under study can be well reproduced. The study indicates that the improved processing techniques providing a smooth interface and a good separation between the 2DEG electrons and the polarization charges should be significant for the quantum device’s performance.