Decomposition of Organometal Halide Perovskite Films on Zinc Oxide Nanoparticles

Research output: Journal Publications and Reviews (RGC: 21, 22, 62)21_Publication in refereed journalpeer-review

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Author(s)

  • Qing-Dan Yang
  • Jingyang Xiao
  • Qifan Xue
  • Zhiqiang Guan

Detail(s)

Original languageEnglish
Pages (from-to)19986-19993
Journal / PublicationACS Applied Materials and Interfaces
Volume7
Issue number36
Online published24 Aug 2015
Publication statusPublished - 16 Sep 2015

Abstract

Solution processed zinc oxide (ZnO) nanoparticles (NPs) with excellent electron transport properties and a low-temperature process is a viable candidate to replace titanium dioxide (TiO2) as electron transport layer to develop high-efficiency perovskite solar cells on flexible substrates. However, the number of reported high-performance perovskite solar cells using ZnO-NPs is still limited. Here we report a detailed investigation on the chemistry and crystal growth of CH3NH3PbI3 perovskite on ZnO-NP thin films. We find that the perovskite films would severely decompose into PbI2 upon thermal annealing on the bare ZnO-NP surface. X-ray photoelectron spectroscopy (XPS) results show that the hydroxide groups on the ZnO-NP surface accelerate the decomposition of the perovskite films. To reduce the decomposition, we introduce a buffer layer in between the ZnO-NPs and perovskite layers. We find that a commonly used buffer layer with small molecule [6,6]-phenyl-C61-butyric acid methyl ester (PC61BM) can slow down but cannot completely avoid the decomposition. On the other hand, a polymeric buffer layer using poly(ethylenimine) (PEI) can effectively separate the ZnO-NPs and perovskite, which allows larger crystal formation with thermal annealing. The power conversion efficiencies of perovskite photovoltaic cells are significantly increased from 6.4% to 10.2% by replacing PC61BM with PEI as the buffer layer.

Research Area(s)

  • buffer layer, decomposition, perovskite solar cell, poly(ethylenimine), zinc oxide nanoparticles

Citation Format(s)

Decomposition of Organometal Halide Perovskite Films on Zinc Oxide Nanoparticles. / Cheng, Yuanhang; Yang, Qing-Dan; Xiao, Jingyang; Xue, Qifan; Li, Ho-Wa; Guan, Zhiqiang; Yip, Hin-Lap; Tsang, Sai-Wing.

In: ACS Applied Materials and Interfaces, Vol. 7, No. 36, 16.09.2015, p. 19986-19993.

Research output: Journal Publications and Reviews (RGC: 21, 22, 62)21_Publication in refereed journalpeer-review