Int. J. Nanotechnol., Vol. 10, Nos. 8/9, 2013 681 Copyright © 2013 Inderscience Enterprises Ltd. Effect of seed particle size and ammonia concentration on the growth of ZnO nanowire arrays and their photoconversion efficiency T.H. Kwon, K. Kim, S.H. Park, A. Annamalai and M.-J. Lee* Department of Advanced Technology Fusion, Konkuk University, 1 Hwayang-dong, Gwangjin-ku, Seoul 143-701, Korea Fax: + 82-2-452-3410 E-mail: graypark21@gmail.com E-mail: rusoa2@gmail.com E-mail: presenthappy@naver.com E-mail: analagappan@gmail.com E-mail: leemtx@konkuk.ac.kr *Corresponding author Abstract: ZnO nanowire arrays were synthesised for dye-sensitised solar cell applications using the chemical bath deposition technique. To study the effect of the particle size in the seed layer on the growth and resultant photoconversion efficiency, we prepared various seeded FTO substrates by repeating the seed layer sol-gel coating process. It was found that changing the number of coating process merely increases the particle size of the ZnO seeds, and the increase in the seed particle size induces low growth rates. In addition, to enhance the nanowire growth rates, ammonia was added with polyethylenimine. Based on various characterisations such as XRD, SEM, and J-V curves, we discuss the effect of ammonia on the growth rates of ZnO nanowire, and suggest the optimum ammonia concentration for solar cell applications. Keywords: ZnO nanowire arrays; seed layer; ammonia; photovoltaic; DSSC. Reference to this paper should be made as follows: Kwon, T.H., Kim, K., Park, S.H., Annamalai, A. and Lee, M.-J. (2013) ‘Effect of seed particle size and ammonia concentration on the growth of ZnO nanowire arrays and their photoconversion efficiency’, Int. J. Nanotechnol., Vol. 10, Nos. 8/9, pp.681–691. Biographical notes: T.H. Kwon received his BS degree in the Department of Materials Chemistry from Konkuk University, Seoul, Korea, in 2011. He is currently a MS candidate in the Department of Advanced Technology Fusion at the same University. His research interests include photovoltaic materials, secondary batteries, and low-dimensional structure synthesis. K. Kim received his BS degree in the Department of Materials Chemistry from Konkuk University, Seoul, Korea, in 2011. He is pursuing his MS degree in the Department of Advanced Technology Fusion at the same University. He is focusing on Li-ion battery materials and chalcopyrite solar cells.