PbTiO3 as Electron-Selective Layer for High-Efficiency Perovskite Solar Cells: Enhanced Electron Extraction via Tunable Ferroelectric Polarization

Ming Zi Wang, Hong Jian Feng, Chong Xin Qian, Jiawei He, Jiangshan Feng, Yong Hua Cao, Kang Yang, Zun Yi Deng, Zhou Yang, Xi Yao, Jianping Zhou, Shengzhong (Frank) Liu, Xiao Cheng Zeng

Research output: Contribution to journalArticle

3 Scopus citations

Abstract

PbTiO3 (PTO) is explored as a versatile and tunable electron-selective layer (ESL) for perovskite solar cells. To demonstrate effectiveness of PTO for electron–hole separation and charge transfer, perovskite solar cells are designed and fabricated in the laboratory with the PTO as the ESL. The cells achieve a power conversion efficiency (PCE) of ≈12.28% upon preliminary optimization. It is found that the PTO ferroelectric layer can not only increase the PCE, but also tune the photocurrent via tuning PTO's ferroelectric polarization. Moreover, to understand the physical mechanism underlying the carrier transport by the ferroelectric polarization, the electronic structure of PTO/CH3NH3PbI3 heterostructure is computed using the first-principles methods, for which the triplet state is used to simulate charge transfer in the heterostructure. It is shown that the synergistic effect of type II band alignment and the specific ferroelectric polarization direction provide the effective extraction of electrons from the light absorber, while minimize recombination of photogenerated electron–hole pairs. Overall, the ferroelectric PTO is a promising and tunable ESL for optimizing electron transport in the perovskite solar cells. The design offers a different strategy for altering direction of carrier transport in solar cells.

Original languageEnglish (US)
Article number1806427
JournalAdvanced Functional Materials
Volume29
Issue number1
DOIs
StatePublished - Jan 4 2019

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Keywords

  • PbTiO
  • electron-selective layers
  • ferroelectric tuning
  • perovskite solar cells

ASJC Scopus subject areas

  • Chemistry(all)
  • Materials Science(all)
  • Condensed Matter Physics

Cite this

Wang, M. Z., Feng, H. J., Qian, C. X., He, J., Feng, J., Cao, Y. H., Yang, K., Deng, Z. Y., Yang, Z., Yao, X., Zhou, J., Liu, S. F., & Zeng, X. C. (2019). PbTiO3 as Electron-Selective Layer for High-Efficiency Perovskite Solar Cells: Enhanced Electron Extraction via Tunable Ferroelectric Polarization. Advanced Functional Materials, 29(1), [1806427]. https://doi.org/10.1002/adfm.201806427