Investigation of the optical and electrical properties of ZnO/Cu/ZnO multilayers grown by atomic layer deposition

Transparent conducting oxides (TCOs) with ZnO/Cu/ZnO sandwich structure grown by atomic layer deposition (ALD) were investigated. The optical and electrical properties of the ZnO/Cu/ZnO multilayers with different Cu thickness were studied by optical spectrometry and four-point probe measurements, respectively. The structural properties were investigated using x-ray diffraction and high resolution tansmission electron microscopy. The experiment results indicated that the thickness of copper has a significant influence on the photoelectrical properties of films. A average transmittance of over 65% at visual wavelength and low resistivity of ∼3.05 × 10−4Ω·cm were obtained when the thickness of Cu was 14 nm. The obtained results inspire us that ALD method is one of candidates for preparing high quality TCO films with high transmittance and low resistivity.