Low-Temperature Processed Brookite Interfacial Modification for Perovskite Solar Cells with Improved Performance

Jiandong Yang; Jun Wang; Wenshu Yang; Ying Zhu; Shuang Feng; Pengyu Su; Wuyou Fu

doi:10.3390/nano12203653

Low-Temperature Processed Brookite Interfacial Modification for Perovskite Solar Cells with Improved Performance

Nanomaterials (Basel). 2022 Oct 18;12(20):3653. doi: 10.3390/nano12203653.

Authors

Jiandong Yang¹, Jun Wang², Wenshu Yang¹, Ying Zhu¹, Shuang Feng³, Pengyu Su⁴, Wuyou Fu¹

Affiliations

¹ State Key Laboratory of Superhard Materials, Jilin University, Changchun 130012, China.
² School of Physics and Optoelectronic Engineering, Shandong University of Technology, Zibo 255000, China.
³ College of Mathmatics and Physics, Inner Mongolia Minzu University, Tongliao 028000, China.
⁴ School of Electronic Information Engineering, Yangtze Normal University, Chongqing 408100, China.

Abstract

The scaffold layer plays an important role in transporting electrons and preventing carrier recombination in mesoporous perovskite solar cells (PSCs), so the engineering of the interface between the scaffold layer and the light absorption layer has attracted widespread concern. In this work, vertically grown TiO₂ nanorods (NRs) as scaffold layers are fabricated and further treated with TiCl₄ aqueous solution. It can be found that a thin brookite TiO₂ nanoparticle (NP) layer is formed by the chemical bath deposition (CBD) method on the surface of every rutile NR with a low annealing temperature (150 °C), which is beneficial for the infiltration and growth of perovskite. The PSC based on the TiO₂ NR/brookite NP structure shows the best power conversion of 15.2%, which is 56.37% higher than that of the PSC based on bare NRs (9.72%). This complex structure presents an improved pore filling fraction and better carrier transport capability with less trap-assisted carrier recombination. In addition, low-annealing-temperature-formed brookite NPs possess a more suitable edge potential for electrons to transport from the perovskite layer to the electron collection layer when compared with high-annealing-temperature-formed anatase NPs. The brookite phase TiO₂ fabricated at a low temperature presents great potential for flexible PSCs.

Keywords: brookite; energy band; interfacial modification; nanorods; perovskite solar cell; pore filling.

Grants and funding

This work was financially supported by the National Natural Science Foundation of China (No. 51272086) and Projects in Inner Mongolia University for Nationalities (No. BS531).