Up-conversion luminescence and near-infrared quantum cutting in Y6O5F8:RE3+ (RE = Yb, Er, and Ho) with controllable morphologies by hydrothermal synthesis
作者:Jia Zhang、Yuhua Wang、Linna Guo、Pengyu Dong
DOI:10.1039/c2dt32463f
日期:——
Monodisperse and uniform Y6O5F8:RE3+ (RE = Yb, Er, and Ho) microarchitectures with various morphologies have been constructed by a facile surfactant-assisted hydrothermal route, and their up-conversion luminescence and NIR quantum cutting properties were investigated. Hollow hexagonal prisms, microbundle gatherings by rods, and solid hexagonal prisms were designed by employing CTAB, PVP, and EDTA as additives, respectively. Under 980 nm excitation, the Y5.34O5F8:0.6Yb3+, 0.06Er3+ samples obtained using different additives exhibit similar emission spectra profiles with predominating peaks at 670 nm; the Y5.34O5F8:0.6Yb3+, 0.06Ho3+ samples give green emissions with the strongest peaks around 544 nm. The NIR quantum cutting for the Y6O5F8:Yb3+, Ho3+ samples was identified by the NIR emission spectra upon both 360 and 450 nm excitation. The corresponding quantum cutting mechanisms were discussed through the energy level diagrams, in which a back-energy-transfer from Yb3+ to Ho3+ was first proposed to interpret the spectral characteristics. A modified calculation equation for the quantum efficiency of Yb3+–Ho3+ coupled by exciting at 450 nm was suggested according to the quantum cutting mechanism. The efficient NIR luminescence and quantum cutting in Yb3+, Ho3+ co-doped Y6O5F8 reveal a possible application in modifying the solar spectrum to enhance the efficiency of silicon solar cells.
通过简单的表面活性剂辅助水热路线构建了具有各种形貌的单分散均匀的 Y6O5F8:RE3+(RE = Yb、Er 和 Ho)微结构,并研究了它们的上转换发光和近红外量子切割特性。分别采用 CTAB、PVP 和 EDTA 作为添加剂设计了空心六角柱、棒状微束聚集和实心六角柱。在 980 nm 激发下,使用不同添加剂获得的 Y5.34O5F8:0.6Yb3+、0.06Er3+ 样品表现出相似的发射光谱曲线,主峰位于 670 nm; Y5.34O5F8:0.6Yb3+、0.06Ho3+ 样品发出绿光发射,最强峰值在 544 nm 附近。 Y6O5F8:Yb3+、Ho3+ 样品的近红外量子切割通过 360 和 450 nm 激发下的近红外发射光谱来确定。通过能级图讨论了相应的量子切割机制,其中首先提出了从Yb3+到Ho3+的反向能量转移来解释光谱特性。根据量子切割机制,提出了一种修正的450 nm激发耦合Yb3+-Ho3+量子效率的计算方程。 Yb3+、Ho3+ 共掺杂 Y6O5F8 的高效近红外发光和量子切割揭示了在改变太阳光谱以提高硅太阳能电池效率方面的可能应用。