Enhancement Mechanism of the Conversion Effficiency of Dye-Sensitized Solar Cells Based on Nitrogen-, Fluorine-, and Iodine-Doped TiO₂ Photoanodes

Abstract

We investigated the electronic structures of N, F, and I doped anatase TiO 2 to explore the enhancement mechanism of incident photon-to-current conversion efficiency (IPCE) in dye-sensitized solar cells (DSSCs) based on N, F, and I doped anatase TiO 2 photoanodes. The hybrid density functional calculation results indicate that n-type F and I doping is better than p-type N doping. The incorporation of I dopant is very favorable to improve the conductivity, the open-circuit voltage, and the visible-light absorption of anatase TiO 2 . Moreover, the I doping can facilitate the electron injection from the dye molecule to the TiO 2 substrate by analyzing the calculated electronic properties of adsorbed dye/TiO 2 complexes. As a result, the I doping can significantly enhance the IPCE of DSSCs. In addition, it is found that the metallic n-type doping on the Ti site of the TiO 2 photoanode can be an effective approach to improve the performance of DSSCs. It is expected that this work can provide valuable information for the development of TiO 2 -based DSSCs.

Titanium Dioxide: From Engineering to Applications

“…To extend the visible light response of TiO 2 and improve its photocatalytic activities, various modification strategies, such as dye sensitization, impurity or intrinsic doping or semiconductor coupling, have been developed [21][22][23]. Among them, introducing impurity ions into the TiO 2 crystal lattice to substitute the host anions and/or cations has earned much attention in the past decade.…”

Doping of TiO2for sensitized solar cells

“…148 DFT calculations predict that I 5+ doping can improve conductivity, V OC and light absorption. 151…”

“…Density functional theory (DFT) has become a popular method due to its low computational cost, making it possible to quickly screen dopants for their suitability to increase TiO 2 properties. 151,199 However, caution must be taken as the band gap is often underestimated, leading to inaccurate predictions. 257…”

Immobilization of TiO2 Nanoparticles on Chlorella pyrenoidosa Cells for Enhanced Visible-Light-Driven Photocatalysis

“…To overcome these problems, tremendous efforts have been devoted to enhancing its photocatalytic capacity. So far, traditional methods, including semiconductor coupling [ 7 , 8 ], metal-ion doping, anion doping [ 9 , 10 ], noble metal loading [ 11 ], and dye sensitization [ 12 ] have been explored.…”