Electroluminescence and Photoluminescence from Nanostructured Diatom Frustules Containing Metabolically Inserted Germanium

Diatoms are single-celled algae that possess silica shells called “frustules” decorated with periodic structures ordered at the micro- and nanoscale. Diatom biosilica containing metabolically inserted germanium is used to fabricate an electroluminescent (EL) thin film device (see figure). The EL spectrum has a series of sharp UV line emissions at 340–380 nm and weaker bands in the blue and red range.