Formation and luminescence of p-type porous polycrystalline silicon

Luminescent porous silicon (PS) was obtained by galvanostatic electrochemical anodisation of p-type polycrystalline silicon (poly-Si) film in aqueous hydrofluoric acid (HF)/ethanol electrolyte. Poly-Si film was prepared and boron delta-doped on n-type silicon wafers by low pressure chemical vapor deposition (LPCVD) process. Porous poly-Si surface morphology varied as a function of anodisation time. Scanning electron microscope (SEM) images have shown macro-porous Si formation along grain boundaries. S-band photo-luminescence (PL) was measured in all samples, while Raman measurements indicated minimal or no confinement effects.