Argonne National Laboratory

Research Highlight | Center for Nanoscale Materials

New route to nontoxic, high-quality quantum dots with control over optoelectronic properties
In a Journal of the American Chemical Society paper, scientists report a novel molten-salt cation exchange method with which to synthesize In1-ₓGaₓP quantum dot emitters with desirable optoelectronic traits.
Upper left: Reaction scheme showing conditions for In-to-Ga cation exchange starting with InP and the subsequent ZnS shelling step to yield bright In₁₋ₓGaₓP/ZnS core-shell particles with photoluminescence quantum yields exceeding 80%. Bottom left: Photographs of In₁₋ₓGaₓP/ZnS samples with increasing gallium content. Right: Time-resolved photoluminescence as function of increasing gallium content in samples.

Scientific Achievement

A reaction scheme using molten-salt cation exchange was developed to produce high-quality In1–xGaxP/ZnS quantum dot emitters with desirable optoelectronic traits. The photoluminescence quantum yields exceeded 80% for x = 0.14−0.57.

Significance and Impact

The results suggest that the band structure of materials such as In1–xGaxP/ZnS can be tuned from direct to indirect gaps by changing the value of x. This study provided crucial insight for designing next-generation quantum dots for displays and other applications.

Research Details

  • The optoelectronic behavior of these nanocrystals was determined experimentally, and the results agreed with theoretical calculations.

DOI: 10.1021/jacs.3c02709

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About Argonne’s Center for Nanoscale Materials
The Center for Nanoscale Materials is one of the five DOE Nanoscale Science Research Centers, premier national user facilities for interdisciplinary research at the nanoscale supported by the DOE Office of Science. Together the NSRCs comprise a suite of complementary facilities that provide researchers with state-of-the-art capabilities to fabricate, process, characterize and model nanoscale materials, and constitute the largest infrastructure investment of the National Nanotechnology Initiative. The NSRCs are located at DOE’s Argonne, Brookhaven, Lawrence Berkeley, Oak Ridge, Sandia and Los Alamos National Laboratories. For more information about the DOE NSRCs, please visit https://​sci​ence​.osti​.gov/​U​s​e​r​-​F​a​c​i​l​i​t​i​e​s​/​U​s​e​r​-​F​a​c​i​l​i​t​i​e​s​-​a​t​-​a​-​G​lance.

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