Near Infrared Luminescence Of Rare Earth Ions Yb³⁺/Nd³⁺ Sensitized By Transition Metal Ions Mn⁴⁺/Cr³⁺ In Aluminate

Luminescence is the phenomenon of light emission of matter in addition to light radiation caused by thermal radiation.Photoluminescence materials can be used to convert the wavelength of light emitted by some light sources.And the near infrared light around 1000 nm which is just above the band edge of silicon semiconductor and where silicon solar cells exhibit excellent spectral response.Thus phosphors are possible to be used as spectral convertors for silicon-based solar cells which can convert high-energy photons within UV and visible range into near infrared emission around 1000 nm,meeting the demand of improving photovoltaic performance of silicon solar cells.In this paper,the Cr3+,Yb3+ co-doped LaMgAl11O19 spectral conversion materials have been synthesized by solid-state reaction method and the Mn4+,Yb3+/Nd3+ co-doped Y3Al5O12 spectral conversion materials have been synthesized by molten salt method.And the luminescence properties and energy transfer mechanism of the phosphors have been studied in detail.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 LaMgAl11O19phosphor might potentially act as spectral convertor for silicon-based solar cells to enhance the photovoltaic conversion efficiency.The Mn4+,Yb3+/Nd3+ co-doped Y3Al5O12 spectral conversion materials have been synthesized by molten salt method.The phosphors can absorb photons in UV-vis spectral region and then give intense near-infrared emission at around 1029 and 886,1065 nm originated from Yb3+:2F5/2+2F7/2 and Nd3+:2F3/2?4I9/2,2F3/2?4I11/2 transitions,respectively.The doping concentration and temperature dependent luminescence properties have been investigated.A dipole-dipole interaction is responsible for the energy transfer sensitization processes from Mn4+ to Yb3+/Nd3+ ions,which has been confirmed by Dexter's theory and the Yokota-Tanimoto model.It is believed that Mn4+,Mg2+,Yb3+/Nd3+ co-doped Y3Al5O12 phosphor might act as spectral convertor for silicon-based solar cells to enhance the photovoltaic conversion efficiency.