New Publication
In a new study in ACS Nano, Hammel et al. use advanced electron microscopy to track how molten-salt cation exchange transforms indium phosphide arsenide quantum dots into indium gallium phosphide arsenide nanocrystals while preserving their shape and crystal structure. Their analysis shows that gallium rapidly replaces indium at the particle surface before slowly diffusing inward, ultimately leaving an indium-rich core even after extended reaction times. Complementary modeling indicates the exchange is diffusion-limited, helping explain the resulting graded compositions, which may influence optoelectronic performance.
This work was done in collaboration with the Talapin lab at the University of Chicago and supported by STROBE and IMOD NSF STCs.
B. F. Hammel, Z. Zhou, J. C. Ondry, D. V. Talapin, S. Yazdi, G. Dukovic. "Structural and Compositional Evolution of Colloidal In1–xGaxP1–yAsy Nanocrystals during Cation Exchange Revealed by Electron Microscopy." ACS Nano, 2026, DOI: 10.1021/acsnano.5c15614.