Influence of oxygen ions irradiation on the optical properties of photoanodes for dye sensitized solar cell
Amrik Singh1*, Devendra Mohan2, Dharmavir S. Ahlawat1, Sandeep Chopra3
1Material Science Lab., Department of Physics, Chaudhary Devi Lal University, Sirsa, Haryana 125055, India
2Laser Laboratory, Department of Applied Physics, Guru Jambheshwar University of Science &Technology, Hisar 125001, Haryana, India
3Inter-University Accelerator Centre, New Delhi 110067, India
Adv. Mater. Lett., 2017, 8 (4), pp 565-571
Publication Date (Web): Mar 15, 2017
Copyright © 2019 VBRI Press
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 (1x1011 and 1x1012 ions/cm2) at 100 MeV energy. The TiO2 films were also subjected with same ion irradiation at 100 MeV of energy with fluence of 1x1011 ions/cm2 and 5x1012 ions/cm2. At 100 MeV energy of O7+ 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 (O7+) 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 1x1012 ions/cm2 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 1x1012 ions/cm2 and decreased at 5x1012 ions/cm2. It is also confirmed that the absorbance of TiO2 film and TiO2/ITO photoanode increases with irradiation of oxygen ion at fluence of 1x1012 ions/cm2 and decreased at 5x1012 ions/cm2. 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 5x1012 ions/cm2. But the decrease in band gap is also found 3.17 eV at fluence of 1x1012 ions/cm2. However, N719 dye loaded O7+ (1x1012 ions/cm2) irradiated TiO2 film show high absorption as compared to other samples. Thus the dose of O7+ irradiation at fluence 1x1012 ions/cm2 may fabricate more efficient DSSC and consequently future prospective of such type of photoanode materials for dye sensitized solar cells seems to be bright.
Swift heavy ion irradiation, energy losses, dye-sensitized solar cells, optical properties of TiO2 /and ITO thin films, TiO2 / ITO photoanode.