Copyright © 2010 American Scientific Publishers All rights reserved Printed in the United States of America Journal of Nanoscience and Nanotechnology Vol. 10, 4797–4800, 2010 Charge Storage Variations of Organic Memory Devices Fabricated by Using C 60 Molecules Embedded in an Insulating Polymer Layer with Au and Al Electrodes Sung Hwan Cho, Jae Hun Jung, Jung Hoon Ham, Dea Uk Lee, and Tae Whan Kim ∗ Advanced Semiconductor Research Center, Division of Electronics and Computer Engineering, Hanyang University, 17 Haengdang-dong, Seongdong-gu, Seoul, 133-791, Korea Organic memory devices based on a hybrid poly(4-vinyl phenol) (PVP) layer containing Buckminster- fullerene (C 60 ) were formed by using a spin coating method. Capacitance–voltage measurements on Al/C 60 embedded in PVP layer/p-Si (100) devices at 300 K showed a hysteresis with a large flat- band voltage shift due to the existence of C 60 molecules, indicative of the charge storage in the C 60 molecules. The magnitude of the flat-band voltage shift for the memory devices with a hybrid active layer consisting of PVP and C 60 was significantly affected by the type of electrode. The endurance time of the organic memory device fabricated utilizing C 60 nanoparticles embedded in the PVP layer at 300 K was approximately 10 years, indicative of excellent memory endurance ability. Keywords: Organic Memory Device, Flat-Band Voltage, C 60 , PVP, C–V Hysteresis, Electrode. 1. INTRODUCTION Hybrid organic/inorganic nanocomposites have been par- ticularly attractive because of the interest in both inves- tigations of fundamental physical properties and potential applications in electronic and optoelectronic devices, such as organic field-effect transistors, organic light-emitting diodes, and organic solar cells. 1–5 Hybrid organic/inorganic memory devices have emerged as potential candidates for applications in next-generation nonvolatile memory devices. 6–12 Potential applications of nonvolatile memory devices fabricated utilizing hybrid organic/inorganic active layers have driven extensive effort to fabricate various types of memory devices. Even though some studies on hybrid organic/inorganic memory devices consisting of organic/metal/organic structures has been reported, 6–8 the reported hybrid organic/inorganic memory devices require precise control of vacuum or temperature conditions. How- ever, very few studies on hybrid organic/inorganic memory devices by simple methods, such as a spin coating method, have been reported. 13 Furthermore, very few studies on the memory effect in organic/inorganic memory devices based on hybrid organic/inorganic composites have been carried out. 14–17 Some studies concerning memory effects of organic memory devices fabricated utilizing Buckmin- sterfullerene (C 60 molecules) dispersed in organic layers ∗ Author to whom correspondence should be addressed. have been performed. 16–21 However, systematic studies on the effects of electrodes on the electrical properties of the organic memory devices are still necessary to enhance device efficiency. This paper reports data for the effect of different electrodes on the flat-band voltage shift of the capacitance– voltage (C –V ) curve for the organic memory devices fab- ricated using a hybrid poly(4-vinyl phenol) (PVP) layer containing C 60 . The active layer of the organic memory devices was prepared by a spin coating method. C –V mea- surements were carried out to investigate the possibility of memory effects involving C 60 molecules embedded in the PVP layer and to clarify the dependence of the flat-band voltage shift of the C –V curve on the type of electrodes for the fabricated organic memory devices. The endurance ability for the fabricated memory devices has been inves- tigated by measuring the magnitude of flat-band shift vari- ation with the repetition of write/erase cycles. 2. EXPERIMENTAL PROCEDURE The two types of devices used in this study were fabricated on B-doped pre-oxidized p-Si (100) substrates by a spin coating method and consisted of the following structures. The PVP insulating polymer solution ratio in the exper- iment consisted of 18 mg of PVP dissolved in 1 mL of isopropyl alcohol solvent. After the C 60 powder was dis- solved in a toluene solution and ultrasonicated in a bath, J. Nanosci. Nanotechnol. 2010, Vol. 10, No. 7 1533-4880/2010/10/4797/004 doi:10.1166/jnn.2010.1710 4797