Wavelength tunable photoluminescence of ZnO/porous Si nanocomposites

► Zinc oxide/porous silicon nanocomposites were prepared by the sol-gel method. ► The photoluminescence of the nanocomposites is tunable across visible spectrum. ► Color of the nanocomposites can be changed from red to blue correspondingly. ► SiO2 interfacial layer plays important roles in carrier recombinations. ► Mechanisms on the tunability in the photoluminescence are discussed.