Optical and electrical properties of ZnO thin film containing nano-sized Ag particles Chae-Seon Hong & Hyeong-Ho Park & Hyung-Ho Park & Ho Jung Chang Received: 26 June 2005 / Accepted: 10 August 2006 / Published online: 20 May 2008 # Springer Science + Business Media, LLC 2008 Abstract Low-temperature crystallized ZnO thin film was achieved by sol–gel process using zinc acetate dihydrate and 2-methoxyethanol as starting precursor and solvent, respectively. Ag nanoparticles were prepared with uniform size at 4.4 nm by spontaneous reduction method of Ag 2- ethylhexanoate in dimethyl sulfoxide (DMSO). The optical and electrical properties of ZnO thin films containing various contents of Ag-nanoparticles were monitored. Light scattering and charge emission and scattering behaviors of Ag nanoparticles in ZnO film were found. The incorpora- tion of Ag nanoparticles into Al-doped ZnO film was also investigated. The optical transmittance was not degraded but the increase of electrical sheet resistance was found. The effect of Al-dopant on the transmittance and electrical sheet resistance of ZnO film was found too great to distinguish the positive effect of the incorporation of Ag nanoparticles into Al-doped ZnO thin films. Keywords ZnO thin film . Nano-sized Ag particles . Chemical solution deposition 1 Introduction Zinc oxide (ZnO) exhibits numerous characteristics that may enable its efficient utilization in these novel devices. ZnO is n-type semiconductor with a wide band gap of 3.37 eV [1]. It has therefore been considered a promising candidate for the development of light-emitting structures and solar cells. However due to its low conductivity compared to metal, the doping and hybridization with metal-nanoparticles have been investigated [2]. Nanopar- ticles or quantum dots have received considerable attention due to their new quantum phenomena resulted from an increase in band gap with decreasing dimension and discrete electronic states with higher oscillator strength. Especially, Ag nanoparticles have been widely used in the electronics industry for the manufacture of conductive thick film circuits and for the internal electrodes of multilayer ceramic capacitors. It has known that inclusion of nano- particles in the materials offers unique properties in optical and electrical characteristics [3, 4]. Sarto et al. reported the electromagnetic shielding effect by metallic Ag nano- particles in ZnO [5]. Also some researchers have reported that nanoparticles could emit the electrons through the introduction of the various energy sources, especially electric field or some special light illumination. These electrons emitted from the applied electric field could contribute to the conduction of the matrix or gives the unique optical properties to the optical applications, e.g. photochromic effects [6, 7]. The doping of ZnO with 3 + valence cations such as Al and Ga induces a great enhancement in the electrical property of ZnO [8, 9]. However there has been no detailed description on the role of metal-nanoparticles in ZnO, especially doped ZnO. In this work, we investigated the effect of the incorpo- ration of Ag-nanoparticles into ZnO film on the optical and electrical properties of ZnO. Furthermore, to clarify the hybridization effect of undoped or Al-doped ZnO with Ag metal-nanoparticles, Ag nanoparticles were prepared and nano-hybridization effect was investigated with undoped and Al-doped ZnO films. J Electroceram (2009) 22:353–356 DOI 10.1007/s10832-008-9526-y C.-S. Hong : H.-H. Park : H.-H. Park (*) Department of Ceramic Engineering, Yonsei University, Seoul 120-749, South Korea e-mail: hhpark@yonsei.ac.kr H. J. Chang Department of Electronic Engineering, Dankook University, Cheonan-shi, Chungnam 330-714, South Korea