Nonconventional Luminescence of Halogenated Silanes: Mechanistic Insight

Area of Science:

• Materials Science
• Photochemistry
• Quantum Chemistry

Background:

• Nonconventional luminescence in pure liquids is an emerging field.
• Understanding luminescence mechanisms in silicon-based materials is crucial for optoelectronics.

Purpose of the Study:

• To systematically investigate the luminescence properties and emission mechanisms of five halogenated silanes.
• To elucidate the effects of halogen type, substitution position, and temperature on luminescence efficiency, Stokes shift, and phosphorescence lifetime.

Main Methods:

• Fluorescence and phosphorescence spectroscopy.
• Theoretical calculations (at room temperature and 77 K).
• Excitation-emission spectra and electron-hole distribution analysis.

Main Results:

• Chlorosilane (CS) exhibits excellent fluorescence (365 nm) and prolonged low-temperature phosphorescence.
• Iodomethylsilane (IT) shows enhanced phosphorescence due to the heavy-atom effect.
• Halogen substitution reduces the excited-ground state energy gap and modulates electron transfer pathways and spin-coupling.

Conclusions:

• Halogenated silanes display tunable luminescence properties influenced by halogen type and position.
• Chlorosilane (CS) is a promising candidate for optoelectronic applications due to its luminescence characteristics.
• This research provides a theoretical basis for designing high-performance silicon-based optoelectronic materials.