Photoluminescence from C60-coupled porous structures formed on Fe+-implanted silicon

Area of Science:

• Materials Science
• Nanotechnology
• Optoelectronics

Background:

• Silicon (Si) wafers are fundamental to semiconductor technology.
• Iron disilicide (FeSi2) nanocrystallites offer unique optical properties.
• C60 fullerene molecules can modify material characteristics.

Purpose of the Study:

• To develop a porous Si structure with embedded beta-FeSi2 nanocrystallites.
• To investigate the photoluminescence (PL) properties of the structure.
• To functionalize the porous Si with C60 molecules and analyze the resulting nanocomposite's optical behavior.

Main Methods:

• Ion implantation of Fe+ into a p-type Si wafer.
• High-temperature annealing and subsequent anodization to form porous Si with beta-FeSi2 nanocrystallites.
• Chemical coupling of C60 molecules using a silane coupling agent.
• Photoluminescence (PL), PL excitation, Raman scattering, and X-ray diffraction measurements.

Main Results:

• Formation of porous Si with beta-FeSi2 nanocrystallites exhibiting initial PL in the 610-670 nm range.
• PL intensity saturation after three months of air storage.
• A stable, pinned PL peak at 570 nm in the C60-functionalized nanocomposite.
• Distinction between PL originating from C60-related defect states and photoexcited carriers in beta-FeSi2.

Conclusions:

• The study successfully created a novel Si/FeSi2/C60 nanocomposite with tailored luminescent properties.
• The pinned photoluminescence at 570 nm is attributed to C60-related defect states.
• This approach offers a new pathway for optimizing luminescent materials in nanostructures.