Multiple-Function Surface Engineering of SnO2 Nanoparticles to Achieve Efficient Perovskite Solar Cells

Hui Wang; Jifeng Yuan; Jiahao Xi; Jiuyao Du; Jianjun Tian

doi:10.1021/acs.jpclett.1c02682

Multiple-Function Surface Engineering of SnO₂ Nanoparticles to Achieve Efficient Perovskite Solar Cells

J Phys Chem Lett. 2021 Sep 23;12(37):9142-9148. doi: 10.1021/acs.jpclett.1c02682. Epub 2021 Sep 15.

Authors

Hui Wang¹, Jifeng Yuan¹, Jiahao Xi¹, Jiuyao Du¹, Jianjun Tian¹

Affiliation

¹ Beijing Advanced Innovation Center for Materials Genome Engineering, Institute for Advanced Materials and Technology, University of Science and Technology Beijing, 30 Xueyuan Road, Haidian District, Beijing 100083, China.

PMID: 34523942
DOI: 10.1021/acs.jpclett.1c02682

Abstract

The mismatched energy-level alignment and interface defects of the SnO₂ nanoparticles' electron transport layer (ETL) and perovskite layer worsen the efficiency of the perovskite solar cell. Herein, we devise a multiple-function surface engineering of SnO₂ nanoparticles. TBA⁺ ions improve the dispersion and stability of colloidal T-SnO₂ nanoparticles and act as a bridge between the ETL and perovskite layer through the electrostatic interaction with anions, thus suppressing the charge recombination and reducing the energy loss. I^- ions passivate oxygen vacancies of SnO₂ nanoparticles but also halide vacancies of the perovskite layer. Furthermore, the conduction band edge of T-SnO₂ is enhanced to match the energy alignment with the perovskite, which reduces the energy offset for electron transfer. As a result, the champion solar cell based on T-SnO₂ presented a power conversion efficiency of 21.71% with a V_OC of 1.15 V and negligible hysteresis, which are much higher than those of the reference device.