International Journal of Physics and Mathematical Sciences ISSN: 2277-2111 (Online) An Online International Journal Available at http://www.cibtech.org/jpms.htm 2012 Vol. 2 (1) January-March, pp.74-85/Patel Research Article 74 THERMOELECTRIC POWER MEASUREMENTS OF ZIRCONIUM SULPHOSELENIDE SINGLE CRYSTALS Kaushik R Patel * Biogas Research Center, Mahadevbhai Desai Gramseva Mahavidhyalaya, Gujarat Vidyapith, Sadra *Author for Correspondence ABSTRACT Zirconium sulphoselenide single crystals in the form of a series ZrS x Se 3-x . (where 0 ≤ x ≤ 3) were grown by chemical vapour transport technique using iodine as a transporting agent. The thermoelectric power of as grown crystals was measured in the temperature range of 303 K to 773 K. The scattering parameter ‘s’, Fermi energy ‘E F ’, effective density of state ‘N c ’ and effective mass of electron were carried out for zirconium sulphoselenide single crystals. The negative sign of thermoelectric power depicted their n-type nature within the temperature range studied. Key Words: Crystal growth, X-ray Diffraction, Hall Effect, Thermoelectric Effect INTRODUCTION It is well known that the group IV transition metal trichalcogenides have a linear chain structure (Furuseth S et al.,1975). The linear chain of metal atoms is parallel to the growth axis. Six chalcogen atoms surround each metal atom forming distorted trigonal prisms. The crystals are grown in the form of layers and each chain in the layer is displaced from the neighboring chain by half of the unit cell along the growth-axis. These layers are stacked by weak van der Walls bonds between the chalcogen atoms. It is essential to possess a detailed knowledge about all the factors of thermoelectric materials, which determines their properties. The major application of the Seebeck effect is about the thermoelectric thermometry that deals with the conversion of thermal energy into electrical energy. As the non-renewable energy sources get dried up quickly, thermoelectric generation is fast and so catching the interest of scientific community as an environment friendly energy source. The generation of electricity at large scale required semiconducting material with significant improvement in their figure of merit. The principle aim of research and development on the thermoelectric materials is to fabricate semiconductors having the figure of merit as high as possible over the temperature range of application of the devices. It is anticipated that the successful development of such materials will lead to new fields of applications for thermoelectric devices and related technologies based on bulk crystals and films. The thermoelectric power measurements of ZrSe 3 single crystals along the chain axis were carried out in the temperature range of 200 K to 400 K (Ikari et al., 1983). It was observed that the thermoelectric power is negative and increases linearly with the reciprocal of temperature. At room temperature, it is 820 VK -1 . Recently a semiconducting material (Zn 4 Sb 3 ) has been developed, which is relatively inexpensive and can be used in more efficient thermoelectric generators for waste heat recovery and automobile industry applications (Caillat et al., 1997). ZrS x Se 3-x exhibits continuous regions of solid solubility. Diffuse reflectance measurements shows that the ZrS 3-x Se x exhibits semiconducting nature (Brattas and Kjekshus, 1972). These compounds have special interest on account of their structural anisotropy. The need for developing a cheap yet effective method of converting solar energy into electrical or chemical energy stimulated rapid advancement of semiconductor electrochemistry in the past decades. As a result certain useful materials, e.g. metallic chalcogenides that have potential in photovoltaic and photoelectrochemical solar cell studies have attracted attention of crystal growers. Among them, disulphide and diselenide of zirconium present some interesting switching and memory effects (Lee et al., 1969) with some possible application in solid-state solar cell (Tributsch H, 1981).