Nonoxide Sol–Gel Synthesis of Terbium‐Doped Silicon Nitride Phosphors

Abstract

Exposure of solutions of Tb(N(SiMe 3 ) 2 ) 3 with SiCl(NEt 2 ) 3 in THF to dry ammonia results in polymeric xerogels. Heating these gels in ammonia leads to amorphous Tb:SiN x phosphors that exhibit bright green luminescence under UV irradiation. MAS-NMR and combustion analysis show the phosphors to be silicon nitride materials analogous to those typically produced by solgel routes. Photoluminescence behavior is similar to that of Tb:SiN x or Tb:SiO 2 films produced by ion implantation that show good electroluminescence activity.

Sol–gel processing of silicon nitride films from Si(NHMe)4 and ammonia

“…These results suggest that ammonolysis is facile, as previously shown by NMR, 6 but that condensation occurs much less readily in the absence of the triflic acid. Si(NHMe) 4 has been used to produce mixed gels with transition metals 6 or rare earths, 7 but in these cases the presence of the more condensable metal amide species, which are less electronegative and have more readily expandable coordination spheres, may have aided the reactions.…”

“…All of the above is consistent with previous reports of gel-derived silicon nitrides. [5][6][7]9,12,15,16 Combustion analysis showed the 1000 C fired sample to contain <0.1% C, 1.57% H and 34.6% N (39.9% N in Si 3 N 4 but crystalline Si 3 N 4 measured as 34.2% under the same conditions and silicon nitride is quite oxidation resistant at high temperature).…”

“…4 It could also provide a controlled route to incorporate metal ions into silicon nitride films to control basicity or optical properties, as previously achieved for powders. [5][6][7] Sol-gel processing offers a wealth of morphologies in oxide materials, 1 but its scope in nitrides is very limited with the main focus having been on high surface area powdered materials for catalysis. 8 Work on production of films has been very limited.…”

Synthesis and processing of silicon nitride and related materials using preceramic polymer and non-oxide sol-gel approaches

“…The ammonolysis rate of the titanium amide was six times that of the silicon amide, but homogeneous gels were still obtained with a 1:1 ratio of silicon to the other element. The lack of a catalyst in these systems is in contrast to the low reactivity of Si(NHMe)4 by itself [228] and the controlled formation of gels is also in contrast to the behaviour of the metal amides themselves, which would precipitate under these conditions [229,230]. It seems that at these concentrations the condensation reactions must occur at rates that are intermediate between the poorly reactive silicon amide and the more reactive metal amides.…”

Synthesis and methane cracking activity of a silicon nitride supported vanadium nitride nanoparticle composite

“…18 VN has been shown to be a useful catalyst in ammonia decomposition reactions, [19][20][21] amination of ethanol 22 and dehydrogenation of propane. 23 A limited number of studies have attempted to modify the properties of gel-derived silicon nitride materials by incorporating aluminium, 24,25 boron, 10 titanium 26 or terbium 27 into the silicon imidonitride framework, or by using it post-synthesis to support palladium nanoparticles. 28 Reactions starting with mixed Si(NHMe) 4 /metal amide solutions have been used to obtain amorphous M : SiN x composites in which boron, titanium, zirconium or tantalum is distributed in the silicon nitride framework.…”