Colloidal Quantum Dot Inks for Single-Step-Fabricated Field-Effect Transistors: The Importance of Postdeposition Ligand Removal

Daniel M. Balazs, Nisrina Rizkia, Hong-Hua Fang, Dmitry N. Dirin, Jamo Momand, Bart J. Kooi, Maksym V. Kovalenko, Maria Antonietta Loi*

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review

26 Citations (Scopus)
341 Downloads (Pure)

Abstract

Colloidal quantum dots are a class of solution processed semiconductors with good prospects for photovoltaic and optoelectronic applications. Removal of the surfactant, so-called ligand exchange, is a crucial step in making the solid films conductive, but performing it in solid state introduces surface defects and cracks in the films. Hence, the formation of thick, device-grade films have only been possible through layer-by-layer processing, limiting the technological interest for quantum dot solids. Solution-phase ligand exchange before the deposition allows for the direct deposition of thick, homogeneous films suitable for device applications. In this work, fabrication of field-effect transistors in a single step is reported using blade-coating, an upscalable, industrially relevant technique. Most importantly, a postdeposition washing step results in device properties comparable to the best layer-by-layer processed devices, opening the way for large-scale fabrication and further interest from the research community.

Original languageEnglish
Pages (from-to)5626-5632
Number of pages7
JournalACS Applied Materials & Interfaces
Volume10
Issue number6
DOIs
Publication statusPublished - 14-Feb-2018

Keywords

  • colloidal quantum dot
  • field-effect transistor
  • colloidal ink
  • solution-phase ligand exchange
  • blade-coating
  • CHARGE-TRANSPORT
  • HIGH-MOBILITY
  • SOLAR-CELLS
  • NANOCRYSTALS
  • EXCHANGE
  • SOLIDS
  • AMBIPOLAR
  • FILMS
  • PHOTOVOLTAICS
  • DEPOSITION

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