Fluorescence Enhancement in Tb3+/CdS Nanoparticles Doped Silica Xerogels

Abstract

Cadmium sulfide semiconductor nanoparticles along with terbium ions were incorporated in silica xerogels through sol-gel route. The optical absorption and emission spectra confirmed the formation of CdS nanoparticles along with terbium ions in the silica gel. The optical bandgap and size of the CdS nanoparticle were calculated from the absorption spectrum. The TEM measurement was also used to evaluate the average size of the CdS nanoparticles. The fluorescence spectra reveal that the intensity of characteristic emission of terbium ions increases considerably in the presence of CdS nanoparticles even in the gel stage itself and this avoids the need of heating gels at high temperatures. The branching ratios were calculated from the emission spectra using the standard procedure.

Facile synthesis of water-soluble luminescent mesoporous Tb(OH)3@SiO2 core-shell nanospheres

“…The absorption spectra in ethanol displayed an intense band located at 228 nm with a middle intensity band around 306 nm. The absorption at 228 nm originates from the silica parts, which agrees with the spectra of previous observations [25-28], and the middle intensity absorption band at 308 nm likely originates from the terbium hydroxide [26-28]. The spectrum displayed some small intensity absorption transitions in visible region which correspond to the forbidden 4f 8 -4f 7 5d transitions of Tb 3+ ion usually weak in silica matrices.…”

“…The spectrum displayed some small intensity absorption transitions in visible region which correspond to the forbidden 4f 8 -4f 7 5d transitions of Tb 3+ ion usually weak in silica matrices. These prominent levels of terbium ions observed are assigned to the appropriate electronic transitions as 7 F 6 → 5 G 4 (304 nm), 7 F 6 → 5 L 10 (335 nm), and 7 F 6 → 5 G 6 (382 nm) [26-28]. The absorption spectrum confirms the formation of Tb(OH) 3 nanoparticles along with silica surface in the core-shell nanospheres [27].…”

Structural, optical and magnetic studies on non-aqueous synthesized CdS:Mn nanomaterials

“…generate considerable interest towards the II-VI compound semiconductors. Rare earth (RE) (Tb 3+ , Eu 3+ , and Er 3+ ) ions doped nanocrystalline II-VI semiconductors have been intensively studied and their properties have been explored by various authors [6][7][8]. Cadmium sulfide (CdS), one among the II-VI compound semiconducting materials with a direct band gap value of 2.40 eV, can be prepared in the form of thin film, powder and colloid suspension by different experimental techniques such as sputtering, coevaporation, solid state reaction method, microwave irradiation, ultrasonic irradiation or synthesis under high-gravity environment.…”

Effect of CdS nanoparticles on photoluminescence spectra of Tb3 + in sol–gel-derived silica glasses

“…The luminescent complex into porous glasses opens up the possibility of using inorganic species ligands and increasing the luminescence by several orders of magnitude (Reisfeld et al 2000). Much studies have been carried out on the preparation and luminescence properties of Tb 3+ and other rare-earth complexes in sol-gelderived silica matrix (Silversmith et al 2006;Armellini et al 2009;Jyothy et al 2009). Among them, sol-gel technique is versatile and convenient method of preparing transparent optical material at low temperature.…”