Near‐Infrared Quantum Cutting via Downconversion Energy Transfers in Ho³⁺/Yb³⁺ Codoped Tellurite Glass Ceramics

Abstract

The different concentration of Ho3+/Yb3+ codoped tellurite glasses were prepared by high‐temperature melting‐quenching method. On excitation of Ho3+ ions with blue photon at 449 nm as well as ultraviolet (UV) photon at 360 nm, the near infrared emission at 977 nm from Yb3+ and 981, 1020 nm from Ho3+, which could be absorbed by silicon and enhance the efficiency of the silicon‐based solar cell, were observed. The energy‐transfer process of Ho3+ and Yb3+ ions and involved mechanism have been investigated and discussed. The first‐order energy transfer (ET) through cross relaxation and a back ET from Yb3+ to Ho3+ occurred in the near‐infrared quantum cutting (NIR QC) system are proposed and verified. The NIR quantum efficiency achieved 166% when Yb3+ doping concentration is 20 mol%.

Controllable synthesis and selective doping of hexagonal GdF3 and spinel-like Ga2O3 nano-crystals in silicate glass

“…The obtained crystal field strength of 7 Ni 2+ in GC730 is 973 cm -1 , much larger than that in glass (about 600 cm -1 [25]), confirming that Ni 2+ ions experience an octahedral crystal field. By using the calculated crystal field strength and Racah parameter (evaluated to be 866 cm -1 ) and…”

“…84-0942) [15]. 5 Based on the Scherer equation, the mean crystallite size of GdF 3 in GC620 is evaluated to be about 20 nm, while those of GdF 3 and γ-Ga 2 O 3 in GC730 are 35 and 9 nm, respectively.…”

“…So the selective incorporation of multiple dopants into the designed nano-crystals is the key to obtain the desired optical properties [7]. To investigate the distribution of the active ions, the absorption spectra of Ni 2+ single-doped precursor glass before and after heat-treated at different temperatures are measured and displayed in Fig.…”

“…Glass ceramics containing fluoride, chalcogenide, or oxide nano-crystals are developed for application in broadband optical amplifications, white light-emitting diodes, tunable lasers, solar cells, and so on [2][3][4][5]. Recently, a combination of various properties in a glass ceramic allows developing multifunctional materials [6][7][8].…”

“…Importantly, for glass ceramics the key to achieve the desired function is the precipitation of the designed crystalline phase and the selective incorporation of the dopants into it [7,9].…”