Co-sensitization of graphene/TiO2 nanocomposite thin films with ruthenizer and metal free organic photosensitizers for improving the power conversion efficiency of dye-sensitized solar cells (DSSCs). (August 2018)

• Record Type: Journal Article
• Authors: Mehmood, Umer; Ahmad, Syed Haseeb Ali; Khan, Anwar Ul Haq; Qaiser, Asif Ali
• Is Part Of: Solar energy. Volume 170(2018)
• Page Start: 47
• Page End: 55
• Publication Date: 2018-08
• Subjects: Nanocomposites -- Co-sensitization -- Optimized -- Efficiency -- Dye-sensitized solar cell; Solar energy -- Periodicals; Solar engines -- Periodicals; 621.47
• DOI: 10.1016/j.solener.2018.05.051
• Languages: English
• ISSNs: 0038-092X

Abstract

Graphical abstract: Highlights: Efficiency of DSSCs has been increased by employing co-sensitized nanocomposite thin films as photoanodes. TiO2 /N719/RK-1 based DSSC showed PCE of 8.45%, superior to that of individually sensitized DSSCs. Nanocomposites of TiO2 and graphene (GR) have been prepared by varying the composition of GR from 0.05% to 0.2%. TiO2 /0.1%GR nanocomposite film sensitized with optimized N719/RK-1 solution showed the PCE of 9.45% Increase in PCE can be attributed to improve light absorption and improve light harvesting efficiency. Abstract: In this work, the power conversion efficiency (PEC) of dye-sensitized solar cells has been improved by using co-sensitized nanocomposite photoanodes. In the first step, mix dye solutions of ruthenizer (N719) and organic dye (RK-1) have been prepared for the sensitization of pristine TiO2 films. Among these dye solutions, 0.2 mM N719/0.3 mM RK-1 solution gives the highest PCE of 8.45%, which is superior to that of individually sensitized solar cells (N719 = 6.54% and RK-1 = 5.69%). In the second step, nanocomposites of TiO2 and graphene have been prepared by changing the composition of graphene from 0.05% to 0.2%. The dispersion of graphene in TiO2 has been confirmed by transmission electron microscopy (TEM). The optimized dye solution of 0.2 mM N719/0.3 mM RK-1 has been used to sensitize TiO2 /graphene thin films. The solar cell based on TiO2 /0.1%GR nanocomposite film shows the power conversion efficiency of 9.45%, which is about 45% and 66% higher than TiO2 /N719 and TiO2 /RK-1 based DSSCs, respectively. The overall enhancement in PCE can be credited to increase light absorption, improve light harvesting efficiency and fast electron transport, which ultimately enhance the current density of solar cells.