Near-infrared downconversion in Ce3+–Yb3+ co-doped YAG

Group 11 Transition-Metal Halide Monolayers: High Promises for Photocatalysis and Quantum Cutting

“…The traditional rare-earth-based quantum cutting materials exhibit shortcomings, including limited absorption bandwidth and poor ability for absorbing near-ultraviolet light that causes the under-utilization of energy due to the nonradiative process. − Here, the 4-MX monolayers can absorb a solar photon less than 450 nm and then transmit the energy to the quantum cutting materials, thereby releasing two photons larger than 450 nm to be absorbed by the silicon solar cells. Here, we take the common quantum cutting material Ce 3+ –Yb 3+ -codoped Y 3 Al 5 O 12 − to match the MX monolayers. The CBM of the 4-MX monolayers (excluding AgBr) is higher than the lowest 5d energy level Ce 3+ , implying a built-in potential to drive the photogenerated electrons to the 5d level of Ce 3+ upon absorbing one near-ultraviolet photon.…”

Broadband Sensitized Near‐Infrared Quantum Cutting Materials for Silicon Solar Cells: Progress, Challenges, and Perspectives

“…For this purpose, Ce 3þ and Eu 2þ are good candidates because they have a wide 4f-5d absorption band, which effectively absorbs the photon energy in ultraviolet-visible regions and can be employed as sensitizers. [49][50][51][52][53] Furthermore, the emission spectra of Eu 2þ change with the different matrix materials, which is more conducive to matching the emission spectra of the sensitizer with the absorption spectra of the activator, which is very helpful in obtaining a high energy transfer efficiency (ETE).…”

“…According to the Dieke energy level, [39] Yb 3þ has only two energy levels ( 2 F 7/2 ground state and 2 F 5/2 excited state) with an energy level difference of 1.27 eV (corresponding to 980 nm), which matches the bandgap of silicon, so the early quantum cutting luminescent materials applied to the silicon solar cells mainly use Yb 3þ ions as activators. [49,54] The energy level structure and spectra of Nd 3þ ions are very rich and can generate NIR light at 850-1450 nm. The transitions from 4 F 3/2 to 4 I 9/2 , 4 I 11/2, and 4 I 13/2 correspond to NIR emissions with peaks of about 910, 1064, and 1341 nm, respectively.…”