Fabrication of Cu 2 ZnSnS 4 (CZTS) Nanofibers via Electrospinning Burak Zafer Büyükbekar, 1,2 Faruk Özel, 2,3 Hüseyin Şakalak, 1,2 Mahmut Kuş, 2,3 and Mustafa Selman Yavuz 1,2* 1 Selcuk University, Department of Metallurgy and Materials Engineering, Konya, Turkey, selmanyavuz@selcuk.edu.tr 2 Selcuk University, Advanced Technology Research and Application Center, Konya, Turkey 3 Selcuk University, Department of Chemical Engineering, Selcuk University, Konya, Turkey INTRODUCTION Electrospinning is common and easy method to prepare fibers. This method is especially used in many applications, such as drug delivery, biosensing, pharmaceutical industry, tissue engineering and solar cell. The indium-free quaternary chalcogenides (i.e. Cu2ZnSnS4 (CZTS)) have driven much attention for their potential applications in low cost solar cells due to their many advantages including appropriate direct band gap (1.0-1.5 eV), high absorption coefficient, extremely low toxicity, high radiation stability, as well as relative abundance (indium free) of this elements. CZTSs are used in constructing solar cells. Their band gaps are tight and also they have absorption specialty in visible area. They are neither expensive like Ga and In, nor toxic like Se and Cd. Chalgenide based solar cells make possible a critical pathway to cost parity between photovoltaic (PV) and conventional energy sources [1,2]. In this study, we synthesized CZTS nanofibers with the method of electrospinning and metal deposition. The fibers vary between 150- 750 nm as depending on concentration of solution. EXPERIMENTAL Fabrication of the CZTS nanofibers was typically prepared by electrospinning of an aqueous solution containing copper chloride, zinc chloride, and tin (II) chloride. The mixture was mixed and stirred by homogenizer for 20 minutes. Polyvinylpyrrolidone was added to this aqueous solution, and then the final mixture was stirred for a day. The solution was passed through a syringe with a 22 gauge stainless steel needle at the tip. The needle was electrified using a high-voltage DC supply with an applied voltage. The solution was pumped continuously using a syringe pump. Fibers were collected onto a grounded collector (typically, a piece of aluminum foil) and left overnight in air to fully hydrolyze. Finally, the fibers were peeled off from the collector and placed in a crucible. Then, the fibers were allowed to cool down to room temperature. After that, liquid sulfur source was drop casted onto the CZTS fibers for sulfurization. Then, to generate the crystal CZTS fibers, the final composite again was calcinated in air at high temperatures for a few hours [3,4]. As shown in Figure 1and Figure 2, CZTS nanofibers were an average size of 500 nm in diameter with crystalline structures. DISCUSSION Shortly, in this work; we showed fabrication of CZTS nanofibers by using electrospinning method. We obtained nanofibers between 150 and 750 nm in size as depending on concentration of the solutions. Figure 1. SEM image of CZTS nanofibers Figure 2. TEM image of a CZTS nanofiber ACKNOWLEDGEMENTS This work was supported by the Scientific and Technological Research Council of Turkey (TUBITAK Grant 112M096, COST TD1004). * Corresponding author: selmanyavuz@selcuk.edu.tr REFERENCES 1. D.H. Reneker et al. Advanced in applied mechanics 41(2007). 2. T.K. Todorow, K.B. Reuter, D.B. Mitzi, Adv. Mater. 22, E156- E159(2010). 3. D. Lin et al. J. Am. Ceram. Soc., 90, 3664–3666 (2007). 4. H. Wang et al. Materials Letters 60, 2480–2484 (2006).