Stoichiometric control of lead chalcogenide nanocrystal solids to enhance their electronic and optoelectronic device performance

Soong Ju Oh, Nathaniel E. Berry, Ji Hyuk Choi, E. Ashley Gaulding, Taejong Paik, Sung Hoon Hong, Christopher B. Murray, Cherie R. Kagan

Research output: Contribution to journalArticlepeer-review

171 Citations (Scopus)

Abstract

We investigate the effects of stoichiometric imbalance on the electronic properties of lead chalcogenide nanocrystal films by introducing excess lead (Pb) or selenium (Se) through thermal evaporation. Hall-effect and capacitance-voltage measurements show that the carrier type, concentration, and Fermi level in nanocrystal solids may be precisely controlled through their stoichiometry. By manipulating only the stoichiometry of the nanocrystal solids, we engineer the characteristics of electronic and optoelectronic devices. Lead chalcogenide nanocrystal field-effect transistors (FETs) are fabricated at room temperature to form ambipolar, unipolar n-type, and unipolar p-type semiconducting channels as-prepared and with excess Pb and Se, respectively. Introducing excess Pb forms nanocrystal FETs with electron mobilities of 10 cm2/(V s), which is an order of magnitude higher than previously reported in lead chalcogenide nanocrystal devices. Adding excess Se to semiconductor nanocrystal solids in PbSe Schottky solar cells enhances the power conversion efficiency.

Original languageEnglish
Pages (from-to)2413-2421
Number of pages9
JournalACS nano
Volume7
Issue number3
DOIs
Publication statusPublished - 2013 Mar 26
Externally publishedYes

Keywords

  • field-effect transistor
  • lead selenide
  • lead sulfide
  • nanocrystals
  • photovoltaics
  • stoichiometry

ASJC Scopus subject areas

  • Materials Science(all)
  • Engineering(all)
  • Physics and Astronomy(all)

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