Enhanced N719 Dye Adsorption onto Ca and La Doped Mesoporous TiO2 Anodes for Dye-Sensitized Solar Cells

• Published in: Journal of electronic materials Vol. 50; no. 10; pp. 5788 - 5795
• Main Authors: Rafieh, Alwani Imanah, Ekanayake, Piyasiri, Nakajima, Hideki, Mahadi, Abdul Hanif, Abu, Masanizan, Don, Muna Fathiah, Lim, Chee Ming
• Format: Journal Article
• Language: English
• Published: New York Springer US 01.10.2021; Springer Nature B.V
• Subjects: Adsorption; Anode effect; Calcium; Characterization and Evaluation of Materials; Chemistry and Materials Science; Doping; Dye-sensitized solar cells; Dyes; Efficiency; Electronics and Microelectronics; Fine structure; High temperature; Instrumentation; Isotherms; Lanthanum; Materials Science; Nanoparticles; Nucleation; Optical and Electronic Materials; Original Research Article; Photovoltaic cells; Solid State Physics; Titanium dioxide; X ray absorption; N719 dye sensitizer; titanium dioxide; mesoporous; Doping; dye-sensitized solar cell
• ISSN: 0361-5235; 1543-186X
• DOI: 10.1007/s11664-021-09121-1

Calcium (Ca) and lanthanum (La) doping into mesoporous TiO 2 prevents nucleation and growth of particles during synthesis and calcination at high temperature, resulting in smaller particle sizes and a decrease in the band gap of TiO 2 . These collectively have a positive affect on the efficiency of dye-sensitized solar cells (DSSCs) when employed as the anode. When designing an effective DSSC anode, the efficiency of dye adsorption must also be considered. This work investigates the adsorption properties of N719 dye onto La and Ca doped mesoporous TiO 2 anodes for DSSCs. Near edge X-ray absorption fine structure spectroscopy (NEXAFS) identified the presence of La and Ca dopants in the TiO 2 nanoparticles. Performance of DSSCs with Ca and La doped mesoporous TiO 2 anodes demonstrated that doping of TiO 2 enhances the overall efficiency of the devices. Both doped TiO 2 nanoparticles showed higher dye adsorption concentration than that of pure TiO 2 , as shown in Brunauer-Emmett-Teller (BET) characterization. By employing Langmuir and Freundlich isotherms, dye adsorption behaviour was modelled. Pure and Ca doped TiO 2 demonstrated good correlation to both isotherms, whereas La doped TiO 2 only showed good correlation with Langmuir isotherm. Irrespective of its single layer adsorption kinetics, 0.1 mol.% La doped TiO 2 has shown the highest dye adsorption and efficiency due to increase in surface area and oxygen vacancies induced by La doping.