| 초록 |
Al doped zinc oxide(ZnO :Al) thin film with wide bandgap, high transparency and low resistivity could be suitable for fabrication of photovoltaic devices, such as solar cell, flat panel display electrode, and optical waveguides. For these applications, the knowledge about the carrier/excitons relaxation and recombination dynamics, as well as the influence of impurities and defects on the quantum efficiency is essential. In case of ZnO thin films, Photoluminescence(PL) study have been many reported to understand the carrier/exciton dynamical behavior. However, up to now few works have been reported on mechanism of ZnO:Al thin films. In this paper, the results of PL in the RF magnetron sputtered ZnO:Al thin films by change of Al composition are represented. ZnO:Al thin films are deposited on the corning 1737 glass with 10cm×10cm. All processes are performed under the Ar/O2 conditions.The RF power is fixed at 100W and other conditions are summarized in table 1. Thickness and bandgap of all films are obtained about 200nm and 3.1~3.3eV, respectively. The dominant XRD (002) peak at 34o, indicating the established c-axis orientation of AZO film, could be obtained. Electrical properties, such as resistivity, Hall mobility and carrier concentration are measured by Hall effect measurement system. Photoluminescence are measured by Raman PL system with a He-Cd laser(325nm) as the excitation source. PL property of 2wt% Al doped ZnO films is a very strong blue band emission at approximately 2.77eV(448nm) without the UV band emission, indictating non-stoichiometric AZO films. |
