Abstract
Upconversion of sub-band-gap photons has the potential to increase the efficiency of solar cells significantly, but requires modification of the solar cells. In this paper, we present a calculation framework to assess the efficiency of a combined bifacial silicon solar cell upconverter device, which is then used to optimize the solar cell׳s front and rear side anti-reflection coatings. Our calculations show that an upconverter can increase the efficiency of an optimized solar cell by 3.0% relative. Subsequently, planar bifacial n-type silicon solar cells were fabricated with optimized anti-reflection coatings. An upconversion layer – containing the upconverter phosphor β-NaY0.8Er0.2F4 embedded in the polymer perfluorocyclobutyl – was attached to the rear side of the solar cells and an external quantum efficiency arising from the upconversion of sub-band-gap photons of 1.69% was measured under 1508 nm monochromatic excitation with an irradiance of 1091 W/m2. This corresponds to a value of 0.15 (W/cm2)−1 when normalized to the irradiance, constituting a five-fold increase compared to the previously best published normalized values that were achieved without optimized solar cells.
| Language | English |
|---|---|
| Pages | 57-68 |
| Number of pages | 12 |
| Journal | Solar Energy Materials and Solar Cells |
| Volume | 128 |
| Early online date | 29 May 2014 |
| DOIs | |
| Publication status | Published - 30 Sep 2014 |
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Keywords
- anti-reflection coatings
- bifacial solar cells
- efficiency limits
- n-type silicon solar cells
- upconversion
Cite this
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Bifacial n-type silicon solar cells for upconversion applications. / Rüdiger, Marc; Fischer, Stefan; Frank, Judith; Ivaturi, Aruna; Richards, Bryce S.; Krämer, Karl W.; Hermle, Martin; Goldschmidt, Jan Christoph.
In: Solar Energy Materials and Solar Cells, Vol. 128, 30.09.2014, p. 57-68.Research output: Contribution to journal › Article
TY - JOUR
T1 - Bifacial n-type silicon solar cells for upconversion applications
AU - Rüdiger, Marc
AU - Fischer, Stefan
AU - Frank, Judith
AU - Ivaturi, Aruna
AU - Richards, Bryce S.
AU - Krämer, Karl W.
AU - Hermle, Martin
AU - Goldschmidt, Jan Christoph
PY - 2014/9/30
Y1 - 2014/9/30
N2 - Upconversion of sub-band-gap photons has the potential to increase the efficiency of solar cells significantly, but requires modification of the solar cells. In this paper, we present a calculation framework to assess the efficiency of a combined bifacial silicon solar cell upconverter device, which is then used to optimize the solar cell׳s front and rear side anti-reflection coatings. Our calculations show that an upconverter can increase the efficiency of an optimized solar cell by 3.0% relative. Subsequently, planar bifacial n-type silicon solar cells were fabricated with optimized anti-reflection coatings. An upconversion layer – containing the upconverter phosphor β-NaY0.8Er0.2F4 embedded in the polymer perfluorocyclobutyl – was attached to the rear side of the solar cells and an external quantum efficiency arising from the upconversion of sub-band-gap photons of 1.69% was measured under 1508 nm monochromatic excitation with an irradiance of 1091 W/m2. This corresponds to a value of 0.15 (W/cm2)−1 when normalized to the irradiance, constituting a five-fold increase compared to the previously best published normalized values that were achieved without optimized solar cells.
AB - Upconversion of sub-band-gap photons has the potential to increase the efficiency of solar cells significantly, but requires modification of the solar cells. In this paper, we present a calculation framework to assess the efficiency of a combined bifacial silicon solar cell upconverter device, which is then used to optimize the solar cell׳s front and rear side anti-reflection coatings. Our calculations show that an upconverter can increase the efficiency of an optimized solar cell by 3.0% relative. Subsequently, planar bifacial n-type silicon solar cells were fabricated with optimized anti-reflection coatings. An upconversion layer – containing the upconverter phosphor β-NaY0.8Er0.2F4 embedded in the polymer perfluorocyclobutyl – was attached to the rear side of the solar cells and an external quantum efficiency arising from the upconversion of sub-band-gap photons of 1.69% was measured under 1508 nm monochromatic excitation with an irradiance of 1091 W/m2. This corresponds to a value of 0.15 (W/cm2)−1 when normalized to the irradiance, constituting a five-fold increase compared to the previously best published normalized values that were achieved without optimized solar cells.
KW - anti-reflection coatings
KW - bifacial solar cells
KW - efficiency limits
KW - n-type silicon solar cells
KW - upconversion
UR - http://www.scopus.com/inward/record.url?scp=84901929972&partnerID=8YFLogxK
U2 - 10.1016/j.solmat.2014.05.014
DO - 10.1016/j.solmat.2014.05.014
M3 - Article
VL - 128
SP - 57
EP - 68
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 -