Synthesized TiO₂ Mesoporous by Addition of Acetylacetone and Graphene for Dye Sensitized Solar Cells

• Main Authors: Chun-Hao Chang, Chia-Han Chuang, De-Yang Zhong, Jun-Cheng Lin, Chia-Chi Sung, Chun-Yao Hsu
• Format: Article
• Language: English
• Published: MDPI AG 2021-07-01
• Series: Coatings
• Subjects: DSSC; TiO₂ mesoporous; band gap; photovoltaic efficiency
• Online Access: https://www.mdpi.com/2079-6412/11/7/796

This study mixed acetylacetone (Acac, 1, 2, and 3 mL) and graphene powder (GP, 0 wt.%, 0.001 wt.%, 0.003 wt.% and 0.005 wt.%) with TiO₂ mesoporous (TiO₂ powders: 20 g and particle size ~30 nm) to enhance the optoelectronic performances of dye sensitized solar cells (DSSC). Sponge-like structure TiO₂ mesoporous layers is a requirement for obtaining high efficiency DSSC, which ia synthesized by spin-coating techniques. The dense TiO₂ blocking layer (using peroxo-titanium complex) has a uniform, dense structure and completely adheres to the substrates to avoid charge recombination. The X-ray diffraction (XRD) and transmission electron microscopy (TEM) analyses of the TiO₂ films display the anatase type phase with preferred orientation along the (101) direction. After being ball milled, the TiO₂ mesoporous particle size almost remains unchanged. For mixing the Acac with TiO₂, the Raman intensity relatively increased, and the band gap energy (Eg) value decreased from 3.223 eV (for pure TiO₂) to 3.076 eV (for 2 mL Acac). Raman spectroscopy is used to evaluate the GP elements. It can be seen the intensity ratio (I_D/I_G) and (I_2D/I_G) was enhanced when the GP concentration increased. Using mixed Acac 2 mL and GP 0.003 wt.% with a TiO₂ mesoporous, led to increases in the open circuit voltage (V_OC), short circuit current density (J_SC) and fill factor (FF). If a fluorine-doped tin oxide is used instead of an indium tin oxide glass substrate, the photovoltaic efficiency of DSSC increases from 5.45% to 7.24%.