Abstract
Upconversion is a promising technique for harvesting sub-band-gap photons in photovoltaic devices. In this work, the optimum erbium (Er3+) doping within the efficient upconverting host material hexagonal sodium yttrium fluoride (β-NaYF4) is investigated for a wide range of irradiance values and under broadband excitation (80±1 nm). Measurements of the internal photoluminescent quantum yield (iPLQY) have been conducted over two orders of magnitude in irradiance, the corresponding solar concentrations characterised, and the external photoluminescent quantum yield (ePLQY) determined. The iPLQY measurements required calibration due to overlap of absorption and re-emission in the range of 1450-1600 nm. The highest iPLQY was for 20% Er3+ with a value of 10.7±1.2% and a normalised efficiency of (5.43±0.90)×10-4 cm2 W -1 at an irradiance of 1.97±0.24 MW m-2 ((108±13)×103 Suns). More importantly for application to silicon solar cells, the highest ePLQY was for 25% Er3+ and was measured to be 6.6±0.7% ((3.35±0.56)×10-4 cm 2 W-1), which agrees well with monochromatic investigations. The 25% Er3+ sample was shown to be more efficient due to an anomalous increase and broadening of the absorption in comparison to lower concentrations. Furthermore, energy transfer mechanisms are proposed for the reduced efficiency of higher concentrations and depletion of the upconversion luminescence.
| Language | English |
|---|---|
| Pages | 18-26 |
| Number of pages | 9 |
| Journal | Solar Energy Materials and Solar Cells |
| Volume | 128 |
| Early online date | 27 May 2014 |
| DOIs | |
| Publication status | Published - 30 Sep 2014 |
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Keywords
- broad-band excitation
- photoluminescence quantum yield
- silicon photovoltaics
- spectral conversion
- upconversion
Cite this
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Broadband photoluminescent quantum yield optimisation of Er 3+-doped β-NaYF4 for upconversion in silicon solar cells. / MacDougall, Sean K. W.; Ivaturi, Aruna; Marques-Hueso, Jose; Krämer, Karl W.; Richards, Bryce S.
In: Solar Energy Materials and Solar Cells, Vol. 128, 30.09.2014, p. 18-26.Research output: Contribution to journal › Article
TY - JOUR
T1 - Broadband photoluminescent quantum yield optimisation of Er 3+-doped β-NaYF4 for upconversion in silicon solar cells
AU - MacDougall, Sean K. W.
AU - Ivaturi, Aruna
AU - Marques-Hueso, Jose
AU - Krämer, Karl W.
AU - Richards, Bryce S.
PY - 2014/9/30
Y1 - 2014/9/30
N2 - Upconversion is a promising technique for harvesting sub-band-gap photons in photovoltaic devices. In this work, the optimum erbium (Er3+) doping within the efficient upconverting host material hexagonal sodium yttrium fluoride (β-NaYF4) is investigated for a wide range of irradiance values and under broadband excitation (80±1 nm). Measurements of the internal photoluminescent quantum yield (iPLQY) have been conducted over two orders of magnitude in irradiance, the corresponding solar concentrations characterised, and the external photoluminescent quantum yield (ePLQY) determined. The iPLQY measurements required calibration due to overlap of absorption and re-emission in the range of 1450-1600 nm. The highest iPLQY was for 20% Er3+ with a value of 10.7±1.2% and a normalised efficiency of (5.43±0.90)×10-4 cm2 W -1 at an irradiance of 1.97±0.24 MW m-2 ((108±13)×103 Suns). More importantly for application to silicon solar cells, the highest ePLQY was for 25% Er3+ and was measured to be 6.6±0.7% ((3.35±0.56)×10-4 cm 2 W-1), which agrees well with monochromatic investigations. The 25% Er3+ sample was shown to be more efficient due to an anomalous increase and broadening of the absorption in comparison to lower concentrations. Furthermore, energy transfer mechanisms are proposed for the reduced efficiency of higher concentrations and depletion of the upconversion luminescence.
AB - Upconversion is a promising technique for harvesting sub-band-gap photons in photovoltaic devices. In this work, the optimum erbium (Er3+) doping within the efficient upconverting host material hexagonal sodium yttrium fluoride (β-NaYF4) is investigated for a wide range of irradiance values and under broadband excitation (80±1 nm). Measurements of the internal photoluminescent quantum yield (iPLQY) have been conducted over two orders of magnitude in irradiance, the corresponding solar concentrations characterised, and the external photoluminescent quantum yield (ePLQY) determined. The iPLQY measurements required calibration due to overlap of absorption and re-emission in the range of 1450-1600 nm. The highest iPLQY was for 20% Er3+ with a value of 10.7±1.2% and a normalised efficiency of (5.43±0.90)×10-4 cm2 W -1 at an irradiance of 1.97±0.24 MW m-2 ((108±13)×103 Suns). More importantly for application to silicon solar cells, the highest ePLQY was for 25% Er3+ and was measured to be 6.6±0.7% ((3.35±0.56)×10-4 cm 2 W-1), which agrees well with monochromatic investigations. The 25% Er3+ sample was shown to be more efficient due to an anomalous increase and broadening of the absorption in comparison to lower concentrations. Furthermore, energy transfer mechanisms are proposed for the reduced efficiency of higher concentrations and depletion of the upconversion luminescence.
KW - broad-band excitation
KW - photoluminescence quantum yield
KW - silicon photovoltaics
KW - spectral conversion
KW - upconversion
UR - http://www.scopus.com/inward/record.url?scp=84901628130&partnerID=8YFLogxK
U2 - 10.1016/j.solmat.2014.05.004
DO - 10.1016/j.solmat.2014.05.004
M3 - Article
VL - 128
SP - 18
EP - 26
JO - Solar Energy Materials and Solar Cells
T2 - Solar Energy Materials and Solar Cells
JF - Solar Energy Materials and Solar Cells
SN - 0927-0248
ER -