How Can the Introduction of Zr4+ Ions into TiO2 Nanomaterial Impact the DSSC Photoconversion Efficiency? A Comprehensive Theoretical and Experimental Consideration.

Aleksandra Bartkowiak,Oleksandr Korolevych,Malgorzata Makowska-Janusik,Maciej Zalas,Gian Luca Chiarello

doi:10.3390/ma14112955

Aleksandra Bartkowiak, Oleksandr Korolevych + Show 3 more

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https://doi.org/10.3390/ma14112955

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Abstract

A series of pure and doped TiO2 nanomaterials with different Zr4+ ions content have been synthesized by the simple sol-gel method. Both types of materials (nanopowders and nanofilms scratched off of the working electrode’s surface) have been characterized in detail by XRD, TEM, and Raman techniques. Inserting dopant ions into the TiO2 structure has resulted in inhibition of crystal growth and prevention of phase transformation. The role of Zr4+ ions in this process was explained by performing computer simulations. The three structures such as pure anatase, Zr-doped TiO2, and tetragonal ZrO2 have been investigated using density functional theory extended by Hubbard correction. The computational calculations correlate well with experimental results. Formation of defects and broadening of energy bandgap in defected Zr-doped materials have been confirmed. It turned out that the oxygen vacancies with substituting Zr4+ ions in TiO2 structure have a positive influence on the performance of dye-sensitized solar cells. The overall photoconversion efficiency enhancement up to 8.63% by introducing 3.7% Zr4+ ions into the TiO2 has been confirmed by I-V curves, EIS, and IPCE measurements. Such efficiency of DSSC utilizing the working electrode made by Zr4+ ions substituted into TiO2 material lattice has been for the first time reported.

Highlights

Published: 30 May 2021In the last few decades, many scientific papers have focused on research on the generation and storage of energy, e.g., batteries, supercapacitors, wind turbines, heat exchangers [1,2,3,4,5]
These results show that the density functional theory (DFT)/PBE+U method with UTi = 6 eV and JTi = 1 eV reproduces the structure of the a-TiO2 acceptably
Inserting the Zr4+ ions into TiO2 lattice in substituted positions was obtained in this work

Summary

Introduction

Published: 30 May 2021In the last few decades, many scientific papers have focused on research on the generation and storage of energy, e.g., batteries, supercapacitors, wind turbines (wind farm), heat exchangers (geothermal energy) [1,2,3,4,5]. The year 1991 marked a significant milestone in the photovoltaic technology world due to the first highly efficient dye-sensitized solar cells (DSSCs) invented by O’Regan and Grätzel [6] This breakthrough invention has been extensively developed for the last 30 years by worldwide scientists (about 29,770 records of scientific articles may be found in databases). Due to many advantages, such as inexpensive manufacturing costs using non-toxic substrates and leaving a remarkably lower carbon footprint, as well as workability under indoor ambient light, DSSCs are a promising alternative to the other types of solar cells [7] It is still worth developing a technology that uses renewable energy sources such as solar light from an ecological perspective.

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