Enhanced patterned fluorescence from polystyrene through focused electron beam irradiation under various gases

Area of Science:

• Materials Science
• Optics
• Nanotechnology

Background:

• Polystyrene is a common polymer with potential optical applications.
• Tuning fluorescence properties is crucial for developing advanced photonic devices.

Purpose of the Study:

• To develop a novel method for tuning and enhancing fluorescence in irradiated polystyrene.
• To investigate the effects of electron dose and ambient gas on photoluminescence (PL) spectra and yield.

Main Methods:

• Focused electron-beam exposure of polystyrene films in gaseous environments using an environmental scanning electron microscope.
• Varying electron dose (1.8–45 mC cm⁻²) and gas pressures (< 10⁻⁵ to 3 mbar).
• Characterization using confocal microscopy, TEM, EDS, and FTIR spectroscopy.

Main Results:

• Tunable emission wavelength (451–544 nm) and photon yield controlled by electron dose and gas pressure.
• Significant PL intensity enhancement (up to 18x) observed under helium on sapphire substrates compared to high vacuum.
• Highest PL yield achieved on soda lime glass substrates under argon; lower yield on conductive substrates.

Conclusions:

• Localized electron-beam synthesis of fluorophores in polystyrene is controllable via dose and ambient gas pressure.
• This technique offers new possibilities for creating tunable fluorophores for photonics.
• The method enables localized introduction of fluorophores with tailored emission properties through electron-beam patterning.