Structural Characterizations, Optical and Electrical Properties of Zinc Oxide Thin Films Grown by Atomic Layer Deposition Method

In this paper we present the structural, optical and electrical characteristics of ZnO thin films grown for different parameters by the atomic layer deposition (ALD) method. The films were grown on glass and silicon substrates at low temperatures. We used diethyl-zinc (DEZn) and deionized water as zinc and an oxygen sources, respectively. Measurements of surface morphology, photoluminescence at room temperature (RT PL) and Hall Effect were made for ZnO layers. The films obtained at 130°C show the highest carrier concentration (1.1×1019 cm-3) and the lowest resistivity (2.84×10-2 Wcm). The films exhibit mobility up to 19.98 cm2/Vs that we associate to the technological process used.

Defects in ZnO Thin Films Grown By Atomic Layer Deposition

In the present paper, we discuss the influence of point defects on electrical and optical characteristics of ZnO thin films grown by the atomic layer deposition (ALD) method on glass and silicon substrates at low temperature (100°C). Room temperature photoluminescence (RT PL) spectra, secondary ion mass spectroscopy (SIMS), and Hall Effect measurements were made for as-grown ZnO layers. The annealing process was performed in air as well as in N2 atmosphere at 400°C for half an hour. The long annealing resulted in a larger reduction in electron concentration. Simultaneously, an evident increase in carrier's mobility was observed, which may suggest that annealing resulted in a decreased number of native defects in the ZnO layers. Also, it was observed that hydrogen atoms in ZnO samples did not dominate their electrical properties with the increase of electrons concentration.