Absolute quantum cutting efficiency of Tb3+-Yb3+ co-doped glass

Abstract

The absolute quantum cutting efficiency of Tb 3þ-Yb 3þ co-doped glass was quantitatively measured by an integrating sphere detection system, which is independent of the excitation power. As the Yb 3þ concentration increases, the near infrared quantum efficiency exhibited an exponential growth with an upper limit of 13.5%, but the visible light efficiency was reduced rapidly. As a result, the total quantum efficiency monotonically decreases rather than increases as theory predicted. In fact, the absolute quantum efficiency was far less than the theoretical value due to the low radiative efficiency of Tb 3þ (<61%) and significant cross-relaxation nonradiative loss between Yb 3þ ions. V

Dramatic Enhancement of Quantum Cutting in Lanthanide-Doped Nanocrystals Photosensitized with an Aggregation-Induced Enhanced Emission Dye

“…We exploited this superior sensitization capability to design and implement a cascade energy-transfer quantum-cutting process consisting of four steps: (i) UV absorption by AIEE LPs, (ii) FRET between excited AIEE LPs and Tb 3+ ions, (iii) quantum cutting by energy transfer from one excited Tb 3+ ion to two excited Yb 3+ ions, and (iv) emission from excited Yb 3+ ions (Figure b,c). As shown in Figure c, the well-matched spectral overlap between emission of our AIEE LPs and absorption of Tb 3+ ions ( 5 D 4 ) can facilitate the FRET process, while Tb 3+ and Yb 3+ ions are a well-known pair for quantum cutting because of their perfect energy matching ( 5 D 4 state of Tb 3+ : 2.53 eV; 2 F 7/2 state of Yb 3+ : 1.265 eV). − The QC emission of Yb 3+ at 1.265 eV is perfectly matched with the most-efficient wavelength of photocurrent generation by a silicon solar cell for further application as discussed below. This QC produces two lower-energy photons from one higher-energy photon, with a theoretical quantum efficiency exceeding 100%. − As an example of the practical utility of AIEE sensitized QC, we demonstrated the improved photovoltaic efficiency of a crystalline silicon solar cell by conversion of one UV photon, at an energy far above the bandgap of silicon, into two NIR photons that match the silicon bandgap and are, thus, efficiently utilized.…”

Yb3+/Tb3+ co-doped GdPO4 transparent magnetic glass-ceramics for spectral conversion

“…Moreover, the 5 D 4 state has a very long lifetime of several milliseconds, which is beneficial for bioassay and short-wavelength laser applications. Furthermore, Tb 3þ exhibits multi-wavelength emission, including ultraviolet, blue, green, and red, which makes it a potential candidate for tunable UC laser [18].…”

Spectroscopic properties of Yb2+ in aluminosilicate glass

“…The optically active ion Yb 3+ is used in high‐power laser materials, laser fibers and scintillator materials but also as sensitizer for energy transfer and up‐conversion processes . Recently, the Yb 3+ ion was proposed to improve the solar cell efficiency by utilizing the quantum cutting effect, as it emits close to the efficiency maximum of silicon‐based solar cells at around 1000 nm . To collect large parts of the solar spectrum, broad band f‐d absorption in the UV to blue spectral region is needed.…”