Synthesis and fabrication of TiO 2 –ZnO nanocomposite based solid state dye sensitized solar cell B. Boro 1 • B. M. Rajbongshi 2 • S. K. Samdarshi 3 Received: 2 January 2016 / Accepted: 23 May 2016 Ó Springer Science+Business Media New York 2016 Abstract TiO 2 , TiO 2 –ZnO (TZ) nanocomposite and PANI (Poly aniline) have been synthesized by simple sol–gel and direct chemical method, respectively, for the application in Dye Sensitized Solar Cell (DSSC). Structural, morpho- logical and optical analyses were carried out using XRD, SEM, EDAX, PL and FTIR. PANI film has been fabricated for solid state DSSC. The photovoltaic performance has been checked for both liquid state and solid state in outdoor and indoor environmental condition. The results show that for TZ showed better performance compared to the monophasic TiO 2 . Stability test showed that the solid state DSSC shows a better stability under constant illumination. Liquid state DSSC loses its efficiency by about 52.5 % while solid state to DSSC by about 13.3 % after 5 h of constant illumination. 1 Introduction The two major limitations in improvement of the conver- sion efficiency of DSSCs are the amount of dye absorption and electron–hole recombination in between the TiO 2 and dye. Many efforts have been made by the researchers for the improvement of this technology. But the success is dependent upon the development of materials and the structure with the objective to get maximum power at minimum cost. An effective method for suppressing the charge recombination is to develop composite of the semiconductor nanomaterials with other wide band gap metal oxides such as ZnO [1–3], MgO [4], CuO [5] etc. which increases the physical separation of the injected electrons from the redox electrolyte through the formation of an inherent energy barrier. Out of these, ZnO has received much attention owing to its band gap energy (3.3 eV), which is similar to TiO 2 (3.2 eV) [6, 7]. Its higher electronic mobility (115–155 cm 2 V -1 s -1 ) is more favorable for electron transport, which helps to reduce the recombination loss of photogenerated electrons in DSSC. The high stability of TiO 2 and the high electronic mobility of ZnO improve the process of electron and hole transfer between the corresponding conduction and valence bands [8]. So, ZnO has been used in different configuration and composition with TiO 2 as a photo anode in DSSC to facilitate enhancement in the surface area for high absorption of dye and increase the electron transport rate to reduce the charge recombination [9, 10]. Although the energy conversion efficiency (g) of DSSCs with liquid electrolyte containing (I - /I 3 - ) has reached as high as 11.5 %, but the device has significant technological problems due to the use of iodine like leak- age, degradation, stability and corrosive nature of iodine in the presence of air and water which can degrade Pt counter electrode. Again iodine electrolyte can absorb visible light of wavelength 430 nm which results in losses in the pho- tocurrent in DSSC [11, 12]. So replacing the iodide elec- trolyte is of prime importance to overcome the its limitation and many endeavors have been made in this & S. K. Samdarshi drsksamdarshi@rediffmail.com B. Boro bibha@tezu.ernet.in 1 Department of Energy, Tezpur University, Tezpur, Assam 784028, India 2 Department of Energy Engineering, North Eastern Hill University, Shillong, Meghalaya, India 3 Centre for Excellence in Green and Efficient Energy Technology, Centre for Energy Engineering, Central University of Jharkhand, Ranchi, Jharkhand 835205, India 123 J Mater Sci: Mater Electron DOI 10.1007/s10854-016-5062-8