In/Ga-free, inkjet-printed charge transfer doping for solution-processed ZnO

Seong Hun Yu, Beom Joon Kim, Moon Sung Kang, Se Hyun Kim, Jong Hun Han, Jun Young Lee, Jeong Ho Cho

Research output: Contribution to journalArticlepeer-review

31 Citations (Scopus)


An In/Ga-free doping method of zinc oxide (ZnO) is demonstrated utilizing a printable charge transfer doping layer (CTDL) based on (3-aminopropyl) triethoxysilane (APS) molecules. The self-assembled APS molecules placed on top of ZnO thin films lead to n-type doping of ZnO and filling shallow electron traps, due to the strong electron-donating characteristics of the amine group in APS molecules. The CTDL doping can tune the threshold voltage and the mobility of the ZnO thin-film transistors (TFTs) as one varies the grafting density of the APS molecules and the thickness of the underneath ZnO thin films. From an optimized condition, high-performance ZnO TFTs can be achieved that exhibit an electron mobility of 4.2 cm2/(V s), a threshold voltage of 10.5 V, and an on/off current ratio larger than 107. More importantly, the method is applicable to simple inkjet processes, which lead to produce high-performance depletion load ZnO inverters through selective deposition of CTDL on ZnO thin films.

Original languageEnglish
Pages (from-to)9765-9769
Number of pages5
JournalACS Applied Materials and Interfaces
Issue number19
Publication statusPublished - 2013 Oct 9

All Science Journal Classification (ASJC) codes

  • Materials Science(all)


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