Enabling Ambipolar to Heavy n-Type Transport in PbS Quantum Dot Solids through Doping with Organic Molecules

Mohamad Insan Nugraha, Shohei Kumagai, Shun Watanabe, Mykhailo Sytnyk, Wolfgang Heiss, Maria Antonietta Loi*, Jun Takeya

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

33 Scopus citations


PbS quantum dots (QDs) are remarkable semiconducting materials, which are compatible with low-cost solution-processed electronic device fabrication. Understanding the doping of these materials is one of the great research interests, as it is a necessary step to improve the device performance as well as to enhance the applicability of this system for diverse optoelectronic applications. Here, we report the efficient doping of the PbS QD films with the use of solution-processable organic molecules. By engineering the energy levels of the donor molecules and the PbS QDs through the use of different cross-linking ligands, we are able to control the characteristics of PbS field-effect transistors (FETs) from ambipolar to strongly n-type. Because the doping promotes trap filling, the charge carrier mobility is improved up to 0.64 cm2 V-1 s-1, which is the highest mobility reported for low-temperature processed PbS FETs employing SiO2 as the gate dielectric. The doping also reduces the contact resistance of the devices, which can also explain the origin of the increased mobility.

Original languageEnglish (US)
Pages (from-to)18039-18045
Number of pages7
JournalACS Applied Materials and Interfaces
Issue number21
StatePublished - May 31 2017

Bibliographical note

Publisher Copyright:
© 2017 American Chemical Society.


  • benzyl viologen
  • doping
  • field-effect transistors
  • ligands
  • quantum dots

ASJC Scopus subject areas

  • General Materials Science


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