Synthesis and optical properties of metal (M) atom-doped polycarbosilane (PCS) with extended conjugation (M = Al, Dy, Er and Eu)

• Al, Dy, Eu and Er were introduced into PCS by one-pot synthesis.
• The PL spectra show a broad blue emission band centered at around 400 nm.
• The introduction of metal atoms can improve oxidation and UV radiation resistance.
• PACS exhibits a PL red-shift, high emission intensity and excellent oxidation resistance.
• PACS with extent σ-conjugation possesses good UV stability due to the AlOx groups.

Optical properties of metal atom-doped polycarbosilane (PCS) which originated from σ-conjugation effect were studied. Al, Dy, Er and Eu were introduced into PCS by one-pot method to yield polyaluminocarbosilane (PACS), polydysprosiumcarbosilane (PDCS), polyerbiumcarbosilane (PErCS) and polyeuropiumcarbosilane (PECS), respectively. Effects of oxidation curing and ultraviolet (UV) radiation on the photoluminescence (PL) properties of the samples were investigated. PL spectra show strong blue light-emissions and the intensity of PCS is enhanced by adding metal atoms. PACS with extended σ-conjugation exhibits an obvious PL red-shift, high intensity, high quantum yield and excellent oxidation resistance as compared with those of others. As treated under UV lamp for 3 h in air, PACS retains good UV resistance performance, owing to the AlOx (x = 4, 5, or 6) groups which effectively extend the σ-conjugation. The obtained results are expected to have important applications in active sources for electroluminescence (EL) devices, especially suitable for blue emission.