Ga-concentration-dependent optical and electrical properties of Ga-doped ZnO thin films prepared by low-temperature atomic layer deposition

摘要

With the vigorous development of information display system and solar energy conversion technology, it is crucial to develop newly indium-free, transparent conductive material (TCO). In this work, Ga-doped ZnO (GZO) thin films with excellent TCO properties were prepared by atomic layer deposition (ALD) at low-temperature. The influence of doping concentration on film performance was studied in detail by X-ray diffractometer, scanning electron microscopy, Hall-effect measurement, X-ray photoelectron spectroscopy and UV-visible spectroscopy. It has been found that the surface morphology of all as-prepared thin films is in irregular grain-like texture, and the preferred orientation and electrical properties of the GZO thin films are highly dependent on Ga-concentration. When the Ga-doping concentration is 1.16 at.% (at ZnO/Ga2O3 cycle ratio of 24:1), the GZO film exhibits the highest carrier concentration of 1.07 x 10(21) cm(-3), the lowest resistivity of 6.91 x 10(-4) Omega cm and the highest quality factor Phi(Tc) of 3.5 x 10(-3) Omega(-1). The average transmittance of the GZO thin films is better than similar to 88%. This study provides an important reference of GZO for TCO film in flexible electronic devices including display devices and other optoelectronic applications.

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