Doping Indium Oxide Films with Amino-Polymers of Varying Nitrogen Content Markedly Affects Charge Transport and Mechanical Flexibility

Zhi Wang*, Xinming Zhuang, Binghao Wang, Wei Huang, Tobin J. Marks, Antonio Facchetti

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

Abstract

Here, correlations between polymer structure and charge transport in solution-processed indium oxide, In2O3:polymer blend flexible thin film transistors (TFTs) are investigated using four polymers having electron-donating amine functionalities (polyethyleneimine (PEI), poly(allylamine), polyethyleneimine ethoxylated (PEIE), and PVP-NH2 (PVP; poly(4-vinylphenol)), and two PEI-PEIE mixtures) with varied atomic amine nitrogen content (N%) of 12.6, 9.1, 6.9, 2.6, respectively. These amino-polymers influence the semiconducting oxide film TFT electron mobilities via a delicate interplay of electron transfer/doping, charge generation/trap-filling, film morphological/microstructural variations, which depend on the polymer structure, thermal stability, and N%, as well as the polymer content of the In2O3 precursor and the carbon residue content in In2O3. Thus, increasing the N% from 0.0% in the control PVP to 12.6% in PEI increases the electron doping capacity, the polymer content of the blend formulation, and the blend TFT field-effect mobility. Optimal polymer incorporation invariably enhances charge transport by as much as ≈2×, leading to a maximum carrier mobility of 8.47 ± 0.73 cm2 V−1 s−1 on rigid Si/SiOx substrates and a remarkable 31.24 ± 0.41 cm2 V−1 s−1 on mechanically flexible polyimide/Au/F:AlOx substrates with Al contacts. Furthermore, all of the polymers equally enhance the mechanical durability of the corresponding In2O3:polymer blend TFTs with respect to mechanical stress.

Original languageEnglish (US)
Article number2100451
JournalAdvanced Functional Materials
Volume31
Issue number33
DOIs
StatePublished - Aug 16 2021

Keywords

  • amino-polymer doping
  • charge transport
  • indium oxide
  • mechanical flexibility

ASJC Scopus subject areas

  • Chemistry(all)
  • Materials Science(all)
  • Condensed Matter Physics

Fingerprint

Dive into the research topics of 'Doping Indium Oxide Films with Amino-Polymers of Varying Nitrogen Content Markedly Affects Charge Transport and Mechanical Flexibility'. Together they form a unique fingerprint.

Cite this