Electrical properties of spray pyrolytic tin sulfide films N. Koteeswara Reddy, K.T. Ramakrishna Reddy * Department of Physics, Sri Venkateswara University, Tirupati-517 502, India Received 19 June 2004; received in revised form 22 December 2004; accepted 6 March 2005 Available online 18 April 2005 The review of this paper was arranged by Prof. S. Cristoloveanu Abstract Tin sulfide (Sn x S y ) films were prepared using spray pyrolysis technique at different substrate temperatures (T s ), (100–450 °C) on Corning 7059 glass substrates. The physical parameters such as electrical resistivity, Hall mobility and net carrier density of the films were determined at room temperature. The films grown in the substrate temperature range, 300–375 °C, were found to be p-type conducting. These SnS films showed average electrical resistivity of 30 X cm, Hall mobility of 130 cm 2 /V s and carrier density, >10 15 cm 3 . The temperature dependence of electrical conductivity of the films was also studied and the activation energies evalu- ated. The results obtained were discussed and reported. Ó 2005 Elsevier Ltd. All rights reserved. PACS: 71.20.Nr; 73; 73.61.r; 74.25.Fy Keywords: SnS films; Electrical properties; Spray pyrolysis; Thermal conductivity and activation energy 1. Introduction Currently, the researchers at various laboratories are investigating new materials for photovoltaic applica- tions with a view to fabricate low-cost solar cell devices. There are a variety of semiconductor materials available today for solar cell fabrication. However, the major problems with these are the initial cost, reliability and reproducibility for scaling up the process for produc- tion. The most extensively studied polycrystalline thin film solar cells are based on GaAs, CuInSe 2 and CdTe as absorber materials. Even though solar cells have been produced using these materials with impressive efficien- cies, the lack of abundancy of indium and the perceived toxicity problems associated with the production and use of Cd-based devices have lead to studies to identify and develop new materials, which are non-toxic and abundant in nature. Dittrich et al. [1] has surveyed many materials for their possible application in solar cells. Among them, the sulfosalts appears to be the promising material. SnS is one of the best compounds in this series, suitable for heterojunction solar cell fabrication, because of its favorable electrical and optical properties. The SnS be- longs to IV–VI group of compounds that exhibits ortho- rhombic structure [2]. It has an absorption coefficient, >10 4 cm 1 with an optical band gap of 1.3 eV [3], above the fundamental absorption. The SnS films have shown p-type conduction with the electrical properties suitably controlled by doping with appropriate dopants like Cl, Ag, N and Sb [4]. In addition, it has the added advan- tage of its constituent elements being abundant in nat- ure, which do not pose any health and environmental hazards. However, the reported data indicates that the physical characteristics of this material have not been 0038-1101/$ - see front matter Ó 2005 Elsevier Ltd. All rights reserved. doi:10.1016/j.sse.2005.03.003 * Corresponding author. Tel.: +91 877 2249666x272; fax: +91 877 2248499/2249999. E-mail address: ktrkreddy@hotmail.com (K.T. Ramakrishna Reddy). www.elsevier.com/locate/sse Solid-State Electronics 49 (2005) 902–906