Our crystals have the added advantage of being tunable, meaning that we can create a specific color of light by adjusting the crystal's size.
Smaller crystals give off blue light, larger ones green or even red.
Korgel and his colleague Keith Johnston created the tiny spherical silicon crystals through a process called arrested precipitation. Then they added pure silicon, which degraded into individual atoms. The octanol chains bound to the silicon atoms, preventing them from recombining into ordinary large crystals. When the solvent evaporated, only the small silicon crystals structures called nanocrystals or quantum dots remained. What controls their size is how many ligands you have.