Cation Exchange in Selenide Nanocrystals (2D)

This 2D cross-section companion visualizes the same topotactic cation-exchange chemistry as the 3D simulator: because the Se²⁻ anion sublattice of a II–VI or IV–VI selenide is far less mobile than its cations, a CdSe nanocrystal can be converted into PbSe or Ag₂Se — a completely different semiconductor with a completely different bandgap — while keeping the exact same size and shape. Instead of a full 3D render, this version slices through the middle of the same lattice and shows the true cross-section of anion and cation sites, driving the identical Arrhenius-activated shrinking-core front and Brus-model bandgap calculation. Choose the guest cation, tune temperature and nanocrystal radius, then drag to pan and scroll to zoom on the reaction front as it eats inward.