On-chip grown ZnO nanosheet-array with interconnected nanojunction interfaces for enhanced optoelectronic NO2 gas sensing at room temperature

Jing Wang, Mingying Yu, Yi Xia, Xian Li, Cheng Yang, Sridhar Komarneni

Research output: Contribution to journalArticlepeer-review

12 Scopus citations


Herein, we demonstrated the on-chip growth of nanostructured ZnO films with abundant nanojunctions for the fabrication of high-performance optoelectronic NO2 sensors. A fast solution approach allowed the controllable growth of ZnO nanorod- and nanosheet-arrays directly on flexible substrates, which were endowed with abundant nanojunctions. Electron microscopy observations revealed the existence of two types of the nanojunction interfaces, i.e., the attached and interconnected interfaces within the nanostructure networks. Compared with the attached nanorods, the optoelectronic NO2 sensors based on interconnected ZnO nanosheets showed higher responses and faster response/recovery rates under UV illumination at room temperature. The responses of the nanosheet-based sensor ranged from 28% to 610% toward NO2 concentrations of 10 ppb to 1000 ppb. Moreover, the optoelectronic sensors exhibited excellent reversibility, and mechanical and long-term stabilities along with low detection limits. The enhanced optoelectronic NO2 sensing properties of the interconnected ZnO nanosheets could be attributed to different types of nanojunction interfaces, which played a key role in modulating the interfacial potential barrier heights of the nanojunctions according to the surface depletion model. The presently developed strategy of nanojunction interface engineering is expected to have wide interest for semiconductor-based sensor applications.

Original languageEnglish (US)
Pages (from-to)19-28
Number of pages10
JournalJournal of Colloid And Interface Science
StatePublished - Oct 15 2019

All Science Journal Classification (ASJC) codes

  • Electronic, Optical and Magnetic Materials
  • Biomaterials
  • Surfaces, Coatings and Films
  • Colloid and Surface Chemistry


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