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Lanthanides (Ln3+) ions-doped materials have unique properties like sharp luminescence arising from downconversion/upconversion, longer lifetimes, large Stokes shift, etc. These properties of Ln3+-doped materials find various applications such as developing optoelectronic devices, lasers, bio imaging, solar cell, etc. However, one of the limitations of the Ln3+ ions is their low absorption coefficient resulting in low luminescence quantum yield (QY). Our strategy is to improve QY of Ln3+-doped materials via sensitization.1 Our first approach is to utilize suitable organic ligands as capping agent and sensitizer. This is achieved by attaching 4,4,4-trifluoro-1-phenyl-1,3 butanedione (TPB) to the surface of Eu3+-doped LiYF4 nanocrystals (NCs). The strong absorbance and energy level overlap of TPB ligands with Eu3+ ions resulted in efficient energy transfer from TBP ligands to Eu3+ ions. The broadband ultraviolet excitation and intense red emission of Eu3+ ions have been explored for the enhancement of solar cell efficiency.2 A ~9 % relative enahncement of photocurrent is noted upon UV excitation. In another approach, Eu3+ ions were sensitized using carbon dots (C-dots) in Eu3+-doped LaF3-C dots nanocomposites.3 This C-dots have high absorbance in ultraviolet (UV) region. Upon UV excitation, C-dots emit in the range of 370 nm to 500 nm and efficiently transfer energy to Eu3+ ions. This energy transfer via C-dots leads to the broadband excitation of Eu3+ ions can have potential use in phosphor based LEDs or solar cell. |