Tuning carrier mobilities and polarity of charge transport in films of CulnSexS2-x quantum dots

Sergiu Draguta, Hunter McDaniel, Victor I Klimov

Research output: Contribution to journalArticle

20 Citations (Scopus)

Abstract

Functional CISeS QD FETs were demonstrated with fairly high charge carrier mobilities. CISeS QDs were synthesized with 60% Se cations. The absorption onset is characterized by a similar wavelength. To fabricate FETs a heavily doped silicon substrate was used as a bottom gate electrode and a 500 nm layer of SiO2 (dry thermal oxide) provides a low-leakage gate dielectric. Films of CISeS QDs were deposited onto the substrate by spin coating at 2500 rpm. In order to make a consistent QD layer thickness of ?50 nm, 4-5 cycles of spin coating separated by 5 min of annealing of the film at 100°C were repeated. For ligand exchange, a 0.5 mmol solution of the new ligand in methanol was spin coated during each cycle after spin coating QDs. Without any treatments, the as-synthesized QD films are conductive despite the presence of bulky ligands and exhibit p-type transport. The mobility increases after treatment with short EDT molecules that replace the original passivation. Interestingly, the QD treatment with Cd2+ ions changes the nature of charge transport and results in ambipolar behavior for both electrons and holes.

Original languageEnglish
Pages (from-to)1701-1705
Number of pages5
JournalAdvanced Materials
Volume27
Issue number10
DOIs
Publication statusPublished - Jan 1 2015

Fingerprint

Carrier mobility
Spin coating
Semiconductor quantum dots
Charge transfer
Tuning
Ligands
Field effect transistors
Conductive films
Gate dielectrics
Silicon
Substrates
Charge carriers
Passivation
Oxides
Methanol
Cations
Ion exchange
Positive ions
Annealing
Ions

ASJC Scopus subject areas

  • Materials Science(all)
  • Mechanics of Materials
  • Mechanical Engineering

Cite this

Tuning carrier mobilities and polarity of charge transport in films of CulnSexS2-x quantum dots. / Draguta, Sergiu; McDaniel, Hunter; Klimov, Victor I.

In: Advanced Materials, Vol. 27, No. 10, 01.01.2015, p. 1701-1705.

Research output: Contribution to journalArticle

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