VIOLET LUMINESCENCE FROM ANODIZED MICROCRYSTALLINE SILICON

Microcrystalline silicon (mu-Si) thin films were anodized in dilute HF solutions in the same manner as forming porous materials. It is demon strated for the first time that the anodized mu-Si thin films show str ong violet luminescence (415 nm) at room temperature. Visible green an d red emissions were also observed accompanying the violet luminescenc e. Structural investigations with scanning electron microscopy indicat e that any formation of micrometer-sized pores which is typical for po rous silicon does not exist in the anodized mu-Si thin films as report ed here. This fact is useful for device applications of silicon-based materials.