Inside Front Cover: Multicolor Photoluminescence from Porous Silicon Using Focused, High‐Energy Helium Ions (Adv. Mater. 1/2006)

Abstract Controlled light emission from porous silicon has been obtained by focused helium beam irradiation prior to electrochemical etching in hydrofluoric acid. The photoluminescence wavelength of porous silicon can be continuously red‐shifted with increasing dose to produce different color emission on a single substrate, as shown in work by E. J. Teo and co‐workers on p. 51. The image features an orange dragon produced on a green background, which clearly shows the longer wavelength emission from the irradiated regions as compared to the un‐irradiated background.