Solar Energy Materials & Solar Cells 89 (2005) 175–183 Novel material for an electrochemical solar cell A ´ . Nemcsics a,c,Ã , S. Kova´ cs b , Z. La´ badi c , K.-F. Hesse d , M. Czank d , P. Turmezei a , S. Motrya b a Institute for Microelectronics and Technology, College of Engineering Budapest, Tavaszmez + o u. 17, H-1084 Budapest, Hungary b Uzhgorod State University, Uzhgorod, Gorki st. 46, 294000 Ukraine c Hungarian Academy of Sciences, Research Institute for Technical Physics and Materials Science, PO Box 49, H-1525 Budapest, Hungary d Institut fu¨r Geowissenschaften und Kristallographie, Universia¨t Kiel, Olshausenstr. 40, D-24098 Kiel, Germany Received 27 September 2004; accepted 22 February 2005 Available online 23 May 2005 Abstract Cd 4 GeSe 6 crystals were grown by chemical vapour transport method. The polycrystalline material was characterised by X-ray, photoelectrochemical and photoluminescence methods. The identification of crystal parameters was refined by X-ray diffraction. Cd 4 GeSe 6 was found to be n-type material with a 1.759 eV direct band gap. The equivalent electrical circuit of Cd 4 GeSe 6 /electrolyte junction was also determined. A possible application field of the examined material in photoelectrochemical energy conversion is suggested. r 2005 Elsevier B.V. All rights reserved. PACS: 82.47.Jk; 78.55.Hx; 72.40.+w; 81.05.Hd Keywords: Electrochemical solar cell; Cd 4 GeSe 6 ; Chemical vapour transport; Electrochemistry; Photo- luminescence; XRD; Impedance analysis ARTICLE IN PRESS www.elsevier.com/locate/solmat 0927-0248/$ - see front matter r 2005 Elsevier B.V. All rights reserved. doi:10.1016/j.solmat.2005.02.012 Ã Corresponding author. Institute for Microelectronics and Technology, College of Engineering Budapest, Tavaszmez + o u. 17, H-1084 Budapest, Hungary. E-mail address: nemcsics.akos@kvk.bmf.hu (A ´ . Nemcsics).