Conversion of broadband UV-visible to near infrared emission by LaMgAl11O19: Cr3+, Yb3+ phosphors

The Cr3+, Yb3+ co-doped LaMgAl11O19 spectral conversion materials have been synthesized by solid-state reaction method. The phosphor can absorb photons in UV-vis spectral region and then give intense near-infrared emission around 980 nm originated from Yb3+: 2F5/2 → 2F7/2 transition. Phonon-assisted energy transfers from Cr3+ ions and Cr3+-Cr3+ ion pairs to Yb3+ ions are both witnessed in LaMgAl11O19 host. The doping concentration and temperature dependent luminescence properties have been investigated. It is believed that Cr3+, Yb3+ co-doped LaMgAl11O19 phosphor might potentially act as spectral convertor for silicon-based solar cells to enhance the photovoltaic conversion efficiency.