A fast-response/recovery ZnO hierarchical nanostructure based gas sensor with ultra-high room-temperature output response

Xiaofang Pan, Xiaojin Zhao, Jiaqi Chen, Amine Bermak, Zhiyong Fan

Research output: Contribution to journalArticle

56 Citations (Scopus)


In this paper, a ZnO hierarchical nanostructure based gas sensor is presented. The proposed implementation features short response/recovery time and ultra-high output response at room temperature (RT). In order to take the advantages of complementary-metal-oxide-semiconductor (CMOS) process in terms of miniaturization and cost-effectiveness, a novel fabrication recipe, consisting of CMOS-compatible techniques, is proposed to form a patterned triple-layer metal, which functions as both interconnection electrodes and catalyst for our reported ZnO hierarchical nanostructure. This enables rapid and local growth of ZnO hierarchical nanostructure directly on a single silicon chip. Reported peak RT output response of 32 (20 ppm NO2) provides a significant 28-fold improvement over the traditional widely adopted nanowire-based gas sensor. Meanwhile, a time efficient gas sensor is also validated by the presented temporal performance with a response and recovery time of 72 s and 69 s, respectively. In addition, compared with the previously demonstrated gas sensors operating at 200-300 °C, the proposed RT sensing completely removes the power-hungry heater and eliminates the related thermal reliability issues. Moreover, the demonstrated process flow well addresses the challenging issues of the traditional mainstream "drop-cast" method, including poor yield, non-uniformity of device performance and low efficiency caused by inevitable manual microscope inspection.

Original languageEnglish
Pages (from-to)764-771
Number of pages8
JournalSensors and Actuators, B: Chemical
Publication statusPublished - 2015
Externally publishedYes



  • CMOS gas sensor
  • Hierarchical nanostructure
  • Room-temperature gas sensing

ASJC Scopus subject areas

  • Electrical and Electronic Engineering
  • Condensed Matter Physics
  • Electronic, Optical and Magnetic Materials
  • Metals and Alloys
  • Surfaces, Coatings and Films
  • Materials Chemistry
  • Instrumentation

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