Photon Upconversion Spectroscopy
401
Er
3+ co-doped bismuth fluoride nanomatrix demonstrates highly sensitive spectral
response to temperature as well as to pressure [33].
Further in a different application, it was demonstrated that, a thin layer of Er/Yb
co-doped UCNPs on the surface of a solar cell can improve its power conversion
efficiency. In principle, Er/Yb doped system can convert NIR light in the range
900–1000 nm and 1500–1600 nm wavelengths to the green and red region through
UC process, where the response of solar cell is high, Fig. 7b. Shalav et al. added
the micron sized NaYF 4 :20% Er
3+ upconverter on c-Si solar cells and found that
external quantum efficiency is increased by 2.5% under 1523 nm excitation [34].
Similarly, Chen et al. also placed a single crystal of LiYF 4 :Yb
3+ , Er
3+ in front of
Fig. 7 a Logarithmic plot of the FIR value with the inverse of temperature for water dispersible
NaYF 4 : Er 3+ , Yb 3+ . Adapted with permission from Ref. [32]. Copyright 2010 American Chemical
Society, b AM 1.5G spectrum showing the fraction (highlighted in cyan) absorbed by the perovskite
solar cell and the spectral regions that can be utilized through upconversion processes. Adapted
with permission from Ref. [35]. Copyright 2016 American Chemical Society, c Time-course plot of
luminescence intensity from a single UCNP, i- Confocal luminescence scan with 980 nm excitation.
(Scale bar = 500 nm), ii- SEM image of this nanocrystal (Scale bar = 10 nm). Adapted with
permission from Ref. [36]. Copyright 2012 American Chemical Society, d Development of latent
fingerprints on glass substrates using NaYF 4 :Yb, Er UCNPs, in dark field and under 980 nm NIR
excitation. The scale bar corresponds to 5.0 mm. Adapted with permission from Ref. [39]. Copyright
2015 American Chemical Society
401
Er
3+ co-doped bismuth fluoride nanomatrix demonstrates highly sensitive spectral
response to temperature as well as to pressure [33].
Further in a different application, it was demonstrated that, a thin layer of Er/Yb
co-doped UCNPs on the surface of a solar cell can improve its power conversion
efficiency. In principle, Er/Yb doped system can convert NIR light in the range
900–1000 nm and 1500–1600 nm wavelengths to the green and red region through
UC process, where the response of solar cell is high, Fig. 7b. Shalav et al. added
the micron sized NaYF 4 :20% Er
3+ upconverter on c-Si solar cells and found that
external quantum efficiency is increased by 2.5% under 1523 nm excitation [34].
Similarly, Chen et al. also placed a single crystal of LiYF 4 :Yb
3+ , Er
3+ in front of
Fig. 7 a Logarithmic plot of the FIR value with the inverse of temperature for water dispersible
NaYF 4 : Er 3+ , Yb 3+ . Adapted with permission from Ref. [32]. Copyright 2010 American Chemical
Society, b AM 1.5G spectrum showing the fraction (highlighted in cyan) absorbed by the perovskite
solar cell and the spectral regions that can be utilized through upconversion processes. Adapted
with permission from Ref. [35]. Copyright 2016 American Chemical Society, c Time-course plot of
luminescence intensity from a single UCNP, i- Confocal luminescence scan with 980 nm excitation.
(Scale bar = 500 nm), ii- SEM image of this nanocrystal (Scale bar = 10 nm). Adapted with
permission from Ref. [36]. Copyright 2012 American Chemical Society, d Development of latent
fingerprints on glass substrates using NaYF 4 :Yb, Er UCNPs, in dark field and under 980 nm NIR
excitation. The scale bar corresponds to 5.0 mm. Adapted with permission from Ref. [39]. Copyright
2015 American Chemical Society