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 demonstrated for the first time that the anodized mu-Si thin films show strong violet luminescence (415 nm) at room temperature. Visible green and red emissions were also observed accompanying the violet luminescence. Structural investigations with scanning electron microscopy indicate that any formation of micrometer-sized pores which is typical for porous silicon does not exist in the anodized mu-Si thin films as reported here. This fact is useful for device applications of silicon-based materials.