Optical Properties of Dy~(3+) Doped Epoxy Novolak Resin

摘要

We report about properties of epoxy novolak resin polymer doped with dysprosium ions. The polymer layers were fabricated by spin-coating onto silicon substrates, or pouring epoxy novolak resin solution into bottomless molds placed on a quartz substrate and leaving them to dry. Rather strong bands around 3366 cm~(-1) in the infrared spectra indicated presence of the O-H groups. Absorption measurements were done in the spectral range from 300 nm to 3000 nm and showed six strong bands at 758 nm (~6F_(3/2)), 807 nm (~6F_(5/3)), 906 nm (~6F_(7/2)), 1100 nm (~6F_(9/2)), 1280 nm (~6F_(11/2)) and 1685 nm (~6H_(11/2)) corresponding to Dy~(3+) ions. Optical band gap E_g was determined from the absorption coefficient values using Tauc's procedure, i.e., from the relationship αhv = A(hv - E_g)~2 and the obtained values varied from 3.489 eV to 3.539 eV depending on the amount of dysprosium ions involved in the samples. Photoluminescence spectra around 1300 nm were investigated by using excitation of He-Ne laser (632.8 nm) and two semiconductor lasers (980 nm and 827 nm).