Research Article 2017, 8(4), 565-571 Advanced Materials Letters Copyright © 2017 VBRI Press 565 Influence of oxygen ions irradiation on the optical properties of photoanodes for dye sensitized solar cell Amrik Singh 1* , Devendra Mohan 2 , Dharmavir S. Ahlawat 1 , Sandeep Chopra 3 1 Material Science Lab., Department of Physics, Chaudhary Devi Lal University, Sirsa, Haryana 125055, India 2 Laser Laboratory, Department of Applied Physics, Guru Jambheshwar University of Science &Technology, Hisar 125001, Haryana, India 3 Inter-University Accelerator Centre, New Delhi 110067 (India) * Corresponding author, E-mail: amrik23kuk@gmail.com Received: 09 March 2016, Revised: 26 September 2016 and Accepted: 03 November 2016 DOI: 10.5185/amlett.2017.6518 www.vbripress.com/aml Abstract Indium Tin Oxide (ITO) coated glass acts as a substrate for photoanode of Dye Sensitized Solar Cells (DSSCs). The ITO substrate was irradiated by oxygen ion with different fluence (1x10 11 and 1x10 12 ions/cm 2 ) at 100 MeV energy. The TiO2 films were also subjected with same ion irradiation at 100 MeV of energy with fluence of 1x10 11 ions/cm 2 and 5x10 12 ions/cm 2 . At 100 MeV energy of O 7+ ion the electronic and nuclear energy loss for TiO2 film have been measured 7.38x10 -1 KeV/nm and 3.8x10 -4 KeV/nm respectively. However, the electronic and nuclear energy loss of ion irradiation for ITO substrate were 7.4x10 -1 KeV/nm and 4.06x10 -4 KeV/nm respectively. Similarly longitudinal/ lateral straggling of ITO and TiO2 have been found 3.87 μm/2.50 μm and 3.62 μm/1.14 μm respectively. Further, the structural and optical properties of these samples were monitored by X-ray diffraction (XRD), scanning electron microscopy (SEM) and UV-visible spectroscopy. It was found that oxygen ion (O 7+ ) irradiation of ITO film has slightly changed the crystallinity and transmission decreases. Furthermore, the particle size of TiO2 thin film has been obtained 80 nm corresponding to (101) plane of XRD pattern. In the case of ITO thin film the crystallite size and band gap changes from 62.35 nm to 53.89 nm and 3.993 eV to 3.971 eV at 1x10 12 ions/cm 2 respectively. Moreover this paper is also reporting that irradiation by swift heavy ion has changed the transmission of the ITO films, and its values decreases as compared to pristine (ITO) which degraded the performance of DSSC. Consequently, a very small value of absorbance is reported for ITO film. However, the absorbance of TiO2 film has found to increase with irradiation of oxygen ion at fluence of 1x10 12 ions/cm 2 and decreased at 5x10 12 ions/cm 2 . It is also confirmed that the absorbance of TiO2 film and TiO2/ITO photoanode increases with irradiation of oxygen ion at fluence of 1x10 12 ions/cm 2 and decreased at 5x10 12 ions/cm 2 . The band gap values of TiO2 thin film were obtained to have a change from 3.37 eV (for pristine) to 3.44 eV at 5x10 12 ions/cm 2 . But the decrease in band gap is also found 3.17 eV at fluence of 1x10 12 ions/cm 2 . However, N719 dye loaded O 7+ (1x10 12 ions/cm 2 ) irradiated TiO2 film show high absorption as compared to other samples. Thus the dose of O 7+ irradiation at fluence 1x10 12 ions/cm 2 may fabricate more efficient DSSC and consequently future prospective of such type of photoanode materials for dye sensitized solar cells seems to be bright. Copyright © 2017 VBRI Press. Keywords: Swift heavy ion irradiation, energy losses, dye sensitized solar cells, optical properties of TiO2 /and ITO thin films, TiO2 / ITO photoanode. Introduction Dye sensitized solar cells (DSSCs) have attracted the researchers due to their low cost, easy fabrication, eco- friendly and high performance [1-2]. The DSSCs consist of a photoelectrode, counter electrode, electrolytes and transparent conducting oxide (TCO) substrate on which dye adsorbed semiconductor oxide layer is coated. The highly transparent ITO (indium doped tin oxide) thin films are having their use in many optoelectronics devices including DSSC. The ITO is a transparent conducting oxide material act as a substrate for the coating of the TiO2 thin films in DSSC which act as photoanode for DSSC [3-5]. However, the TiO2 material has been used in various applications like sensors, antireflection coating, and thin film devices and solar cells [6-11]. The properties of TiO2 has been investigated by many researchers [12] due to its high refractive index, low cost, non-toxicity, good radiation resistance, conversion of light energy into electrical energy and large number of other technological applications. Promising materials have been developed by modification in the structural and