Amplifying Photochromic Response in Tungsten Oxide Films with Titanium Oxide and Polyvinylpyrrolidone
Min-Sung Kim,
Jun-Ho Yoon,
Hong-Mo Kim,
Dong-Jun Lee,
Tamaki Hirose,
Yoshihiko Takeda,
Jae-Pil Kim
Affiliations
Min-Sung Kim
Lab of Organic Photo-Functional Materials, Department of Materials Science and Engineering, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul 08826, Republic of Korea
Jun-Ho Yoon
Lab of Organic Photo-Functional Materials, Department of Materials Science and Engineering, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul 08826, Republic of Korea
Hong-Mo Kim
Semiconductor Analysis Team, Advanced Institute of Convergence Technology, 145 Gwanggyo-ro, Yeongtong-gu, Suwon-si 16229, Republic of Korea
Dong-Jun Lee
Lab of Organic Photo-Functional Materials, Department of Materials Science and Engineering, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul 08826, Republic of Korea
Tamaki Hirose
Hydrogen Related Materials Group, Research Center for Energy and Environmental Materials, National Institute for Materials Science (NIMS), Tsukuba 305-0003, Japan
Yoshihiko Takeda
Hydrogen Related Materials Group, Research Center for Energy and Environmental Materials, National Institute for Materials Science (NIMS), Tsukuba 305-0003, Japan
Jae-Pil Kim
Lab of Organic Photo-Functional Materials, Department of Materials Science and Engineering, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul 08826, Republic of Korea
Tungsten oxide (WO3) is known for its photochromic properties, making it useful for smart windows, displays, and sensors. However, its small bandgap leads to rapid recombination of electron–hole pairs, resulting in poor photochromic performance. This study aims to enhance the photochromic properties of WO3 by synthesizing hexagonal tungsten oxide via hydrothermal synthesis, which increases surface area and internal hydrates. Titanium oxide (TiO2) was adsorbed onto the tungsten oxide to inject additional charges and reduce electron–hole recombination. Additionally, polyvinylpyrrolidone (PVP) was used to improve dispersion in organic solvents, allowing for the fabrication of high-quality films using the doctor blade method. Characterization confirmed the enhanced surface area, crystal structure, and dispersion stability. Reflectance and transmittance measurements demonstrated significant improvements in photochromic properties due to the composite structure. These findings suggest that the introduction of TiO2 and PVP to tungsten oxide effectively enhances its photochromic performance, broadening its applicability in various advanced photochromic applications.
