Comment on "Structural and Electrical Properties of Atomic Layer Deposited Al-Doped ZnO Films"

In a recent report, Lee et al. have proposed an "effective field model" for extrinsic doping to explain the electrical properties of Al-doped zinc oxide (ZnO) films grown by atomic layer deposition (ALD)([1]). They have introduced the doping model by considering the layered structure of the ALD-grown films as observed in the transmission electron microscopy measurements. However, in the present comment, we have demonstrated that the suggested doping model is misleading in which physically inconsistent assumptions are considered throughout. Herein, a reasonable interpretation of the electrical properties and doping mechanism of the ALD-grown films by taking into consideration the theoretical formulations of the disordered electronic system is suggested.