Engineering InAs(x)P(1-x)/InP/ZnSe III-V alloyed core/shell quantum dots for the near-infrared

J Am Chem Soc. 2005 Aug 3;127(30):10526-32. doi: 10.1021/ja0434331.


Quantum dots with a core/shell/shell structure consisting of an alloyed core of InAs(x)P(1-x), an intermediate shell of InP, and an outer shell of ZnSe were developed. The InAs(x)P(1-x) alloyed core has a graded internal composition with increasing arsenic content from the center to the edge of the dots. This compositional gradient results from two apparent effects: (1) the faster reaction kinetics of the phosphorus precursor compared to the arsenic precursor, and (2) a post-growth arsenic-phosphorus exchange reaction that increases the arsenic content. The cores have a zinc blend structure for all compositions and show tunable emission in the near-infrared (NIR) region. A first shell of InP leads to a red-shift and an increase in quantum yield. The final shell of ZnSe serves to stabilize the dots for applications in aqueous environments, including NIR biomedical fluorescence imaging. These NIR-emitting core/shell/shell InAs(x)P(1-x)/InP/ZnSe were successfully used in a sentinel lymph node mapping experiment.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Alloys / chemistry
  • Animals
  • Arsenicals / chemistry*
  • Indium / chemistry*
  • Phosphines / chemistry*
  • Quantum Dots*
  • Rats
  • Selenium Compounds / chemistry*
  • Sentinel Lymph Node Biopsy
  • Spectroscopy, Near-Infrared / methods*
  • X-Ray Diffraction
  • Zinc Compounds / chemistry*


  • Alloys
  • Arsenicals
  • Phosphines
  • Selenium Compounds
  • Zinc Compounds
  • Indium
  • indium arsenide
  • zinc selenide
  • indium phosphide