Photoluminescence signature of resonant energy transfer in ZnO coated Si nanocrystals decorated on vertical Si nanowires array

摘要: We investigate the mechanism of red shift in photoluminescence (PL) and reduction PL lifetime from Si nanocrystals (NCs) decorated on vertical nanowires (NWs) array due to ZnO over layer coating. Arrays vertically aligned single crystalline NWs with arbitrary shaped NCs have been fabricated by a silver assisted wet chemical etching method. A strong broad band tunable visible near-infrared is observed these at room temperature surface are primarily responsible for emission. Higher gap film sputter deposited form heterostructure. Bare NW/NCs NCs/ZnO heterostructures show extremely high absorption entire region. studies reveal significant some cases reduced intensity close proximity NCs. This accompanied after Interestingly, no measurable absence resonance emission energy that The modified explained through an diagram basis resonant transfer defect recombination carries overlayer excites subsequent de-excitation process via radiative recombination. These findings important bearing development cost effective Si-based hybrid optoelectronic devices using wide heterostructured oxide semiconductors.