Pinhole-free TiO2/Ag(O)/ZnO configuration for flexible perovskite solar cells with ultralow optoelectrical loss

Eunwook Jeong, Soohyun Bae, Jong Bae Park, Seung Min Yu, Donghwan Kim, Hae Seok Lee, Jongjoo Rha, Young Rae Cho, Jungheum Yun

Research output: Contribution to journalArticlepeer-review

27 Citations (Scopus)


Perovskite solar cells (PSCs) fabricated on transparent polymer substrates are considered a promising candidate as flexible solar cells that can emulate the advantages of organic solar cells, which exhibit considerable freedom in their device design thanks to their light weight and mechanically flexibility while achieving high photocurrent conversion efficiency, comparable to that of their conventional counterparts fabricated on rigid glasses. However, the full realization of highly efficient, flexible PSCs is largely prevented by technical difficulties in simultaneously attaining a transparent electrode with efficient charge transport to meet the specifications of PSCs. In this study, an effective strategy for resolving this technical issue has been devised by proposing a simple but highly effective technique to fabricate an efficient, multilayer TiO2/Ag(O)/ZnO (TAOZ) configuration. This configuration displays low losses in optical transmittance and electrical conductivity owing to its completely continuous, ultrathin metallic Ag(O) transparent electrode, and any notable current leakage is suppressed by its pinhole-free TiO2 electron transport layer. These features are a direct consequence of the rapid evolution of Ag(O) and TiO2 into ultrathin, completely continuous, pinhole-free layers owing to the dramatically improved wetting of metallic Ag(O) with a minimal dose of oxygen (ca. 3 at%) during sputtering. The TAOZ configuration exhibits an average transmittance of 88.5% in the spectral range of 400-800 nm and a sheet resistance of 8.4 Ω sq-1 while demonstrating superior mechanical flexibility to that of the conventional TiO2 on ITO configuration. The photocurrent conversion efficiency of flexible PSCs is significantly improved by up to 11.2% thanks to an optimum combination of optoelectrical performance and pinhole-free morphologies in the TAOZ configuration.

Original languageEnglish
Pages (from-to)9160-9170
Number of pages11
JournalRSC Advances
Issue number16
Publication statusPublished - 2019

Bibliographical note

Funding Information:
This research was nancially supported by the Fundamental Research Program of the Korea Institute of Materials Science (PNK6100), the Korea Institute of Energy Technology Evaluation and Planning (KETEP) and the Ministry of Trade, Industry & Energy (MOTIE) of the Republic of Korea (No. 20173030014370), the Human Resources Program in Energy Technology of the KETEP and MOTIE (No. 20154030200760), and a grant from Korea University.

Publisher Copyright:
© 2019 The Royal Society of Chemistry.

ASJC Scopus subject areas

  • General Chemistry
  • General Chemical Engineering


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