Silver Nanoclusters Tunable Visible Emission and Energy Transfer to Yb3+ Ions in Co-Doped GeO2-PbO Glasses for Photonic Applications

Abstract

This work investigates the optical properties of Yb3+ ions doped GeO2-PbO glasses containing Ag nanoclusters (NCs), produced by the melt-quenching technique. The lack in the literature regarding the energy transfer (ET) between these species in these glasses motivated the present work. Tunable visible emission occurs from blue to orange depending on the Yb3+ concentration which affects the size of the Ag NCs, as observed by transmission electron microscopy. The ET mechanism from Ag NCs to Yb3+ ions (2F7/2 → 2F5/2) was attributed to the S1→T1 decay (spin-forbidden electronic transition between singlet–triplet states) and was corroborated by fast and slow lifetime decrease (at 550 nm) of Ag NCs and photoluminescence (PL) growth at 980 nm, for excitations at 355 and 405 nm. The sample with the highest Yb3+ concentration exhibits the highest PL growth under 355 nm excitation, whereas at 410 nm it is the sample with the lowest concentration. The restriction of Yb3+ ions to the growth of NCs is responsible for these effects. Thus, higher Yb3+ concentration forms smaller Ag NCs, whose excitation at 355 nm leads to more efficient ET to Yb3+ ions compared to 410 nm. These findings have potential applications in the visible to near-infrared regions, such as tunable CW laser sources and photovoltaic devices.

Tunable Visible Light and Energy Transfer Mechanism in Tm3+ and Silver Nanoclusters within Co-Doped GeO2-PbO Glasses

“…The current investigation highlights the properties of GeO 2 -PbO glasses to serve as hosts for both Tm 3+ ions and Ag NCs, while also elucidating the intricate ET processes among these entities. This work is also motivated by recent results of Yb 3+ -doped GeO 2 -PbO glasses that corroborated the ET mechanism between these species [32]. It also showed the possibility of hosting Ag NCs and Yb 3+ ions in GeO 2 -PbO glasses.…”

“…These compositions span zinc borate CABAl [13], fluorophosphate [14][15][16][17][18][19], borates [20], and borosilicates [21,22], among other glass matrices [23][24][25][26][27], thereby broadening the possibilities of Ag NC-based photonic applications. The applications of this technology span a wide array of photonic advancements, including photovoltaic devices, flexible screens, sources for white light [28], fiber [29,30], including wavelength tuning [31,32]. It is important to note that Ag NCs stand apart from metallic nanoparticles (NPs) due to their unique composition, consisting of only small agglomerates of silver atoms, resulting in an amorphous structural arrangement [16].…”