Interfacial ZnS passivation for improvement of transparent ZnO/CuI diode characteristics

Taehyeon Kim, Changjin Son, Junwoo Lee, Eunseok Oh, Shujie Li, Chih Hung Chang, Sangwoo Lim

Research output: Contribution to journalArticlepeer-review

3 Citations (Scopus)


To fabricate a n-ZnO/p-CuI heterojunction diode with a high rectification ratio at a large junction area, γ-CuI film was spin-coated on ZnO. Since the n-ZnO/p-CuI diode showed a rectification ratio as small as 2.38 × 102, the ZnS interfacial layer was prepared by successive ionic layer adsorption and reaction. By placing a ZnS layer between the n-ZnO/p-CuI, the rectification ratio from the diode increased to 1.71 × 107 at a junction area of 1 cm2. Modification of the valence band offset and the conduction band offset of the n-ZnO/p-CuI junction in the presence of the interfacial ZnS layer may facilitate carrier transport between ZnO and CuI. In addition, it was confirmed that two types of defects (oxygen vacancy and unpaired electron trapped on an oxygen vacancy) were reduced by insertion of an interfacial ZnS layer. A significant improvement in the rectification ratio resulted from the large decrease in the reverse current in the ZnO/CuI diode by a reduced amount of oxygen vacancies. Therefore, the improvement of band alignment with the decrease in the interfacial defects by the introduction of wide bandgap ZnS passivation layer enhanced the electrical characteristics of ZnO/CuI diode.

Original languageEnglish
Article number147645
JournalApplied Surface Science
Publication statusPublished - 2021 Jan 15

Bibliographical note

Funding Information:
This work was supported by the BK21 Plus Program (Globalization Program for Advanced Education of ChE-based Converging Technology, 21A20131812527) and the Basic Science Research Program (NRF-2016R1D1A1B03936347) through the National Research Foundation of Korea (NRF) funded by the Korean Government Ministry of Education . S. Li and C.-H. Chang acknowledge support from the Walmart U.S. Manufacturing Innovation Fund .

Publisher Copyright:
© 2020 Elsevier B.V.

All Science Journal Classification (ASJC) codes

  • Condensed Matter Physics
  • Surfaces, Coatings and Films
  • Surfaces and Interfaces


Dive into the research topics of 'Interfacial ZnS passivation for improvement of transparent ZnO/CuI diode characteristics'. Together they form a unique fingerprint.

Cite this