Titanium Nanopillar Arrays Functioning as Electron Transporting Layers for Efficient, Anti-Aging Perovskite Solar Cells

Jie Zhao, Peng Sun, Zhongwei Wu, Jun Li, Xiaohan Wang, Ting Xiao, Lin Yang, Zijian Zheng, Zhifeng Huang

Research output: Journal article publicationJournal articleAcademic researchpeer-review

2 Citations (Scopus)

Abstract

Electron transporting layers (ETLs), required to be optically transparent in perovskite solar cells (PSCs) having regular structures, possess a determinant effect on electron extraction and collection. Metal oxides (e.g., TiO2) have overwhelmingly served as ETLs, but usually have low electron mobility (μe < 10−2 cm2 V−1 s−1) not favorable for photovoltaic conversion. Here, metal oxides are replaced with metals (e.g., Ti with μe ≈ 294 cm2 V−1 s−1) that are sculptured via glancing angle deposition to be a close-packed nanopillar array (NaPA), which vertically protrudes on a transparent electrode to obtain sufficient optical transmission for light harvesting in perovskite. Ti NaPAs, whose rough surfaces are passivated with 5 nm thick TiO2 (i.e., Ti NaPAs@TiO2) to suppress exciton recombination, lead to the champion power conversion efficiency (PCE) of 18.89% that is superior to that of MAPbI3 PSCs without Ti NaPAs@TiO2 or containing TiO2 NaPAs@TiO2, owing to high surface wettability, high μe, and relatively low work function of Ti. Furthermore, Ti NaPAs@TiO2 effectively prevents the decomposition of MAPbI3 to achieve long-term shelf stability whereby 50-day aging only causes 15% PCE degradation. This work paves the way toward widening the material spectrum, from semiconductors to metals, to generate a diverse range of ETLs for producing efficient optoelectronic devices with long-term shelf stability.

Original languageEnglish
Article number2004778
JournalSmall
Volume17
Issue number2
DOIs
Publication statusPublished - 14 Jan 2021

Keywords

  • electron transporting layers
  • glancing angle deposition
  • perovskite solar cells
  • shelf stability
  • titanium nanopillars

ASJC Scopus subject areas

  • Biotechnology
  • Biomaterials
  • Chemistry(all)
  • Materials Science(all)

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