Infrared reflecting coverglass for multijunction cells in a terrestial high-concentrating photovoltaic system

L. Micheli, N. Sarmah, X. Luo, K.S. Reddy, T.K. Mallick

Research output: Contribution to conferencePaper

Abstract

Multijunction cells are composed of multiple layers of semiconductors, with different bandgaps. Among them, GaInP/GaAs/Ge cells are the most popular ones, due to their high performances [1]. These cells have higher efficiencies that silicon ones and should be really convenient in a concentrating photovoltaic plants. Photons are absorbed by a layer if their energy is equal or higher to the semiconductor bandgap. Otherwise they are transmitted to the lower semiconductor. All the photons with less energy than the lowest bandgap are converted into waste heat. They represent about the 5% of the total solar spectrum [2]. Moreover, the Germanium layer usually produces a higher current that the other subcells and even the excess current is converted into heat. Cooling is an important task in designing CPV: the higher the concentration the higher the temperature. Thus, a passive cooling effort can be obtained reducing the infrared radiation absorbed by the cell. An infrared reflecting layer placed on the top of the cell encapsulation should achieve this goal. This solution should reduce the quote of low-energy photons absorbed by the cell, decreasing both the sunlight directly converted into heat and the sunlight converted into excess current by the Germanium layer. Infrared reflecting coverglasses have been successfully tested on space applications. This research focuses on PMMA application for IR reflecting purposes in a terrestrial high CPV system.

Conference

Conference27th European Photovoltaic Solar Energy Conference and Exhibition
Abbreviated title27th EU PVSEC
CountryGermany
CityFrankfurt
Period24/09/1228/09/12

Fingerprint

Energy gap
Photons
Semiconductor materials
Infrared radiation
Germanium
Cooling
Waste heat
Space applications
Encapsulation
Silicon
Temperature
Hot Temperature

Keywords

  • multijunction solar cell
  • concentrator cells
  • solar cell efficiency
  • semiconductors

Cite this

Micheli, L., Sarmah, N., Luo, X., Reddy, K. S., & Mallick, T. K. (2012). Infrared reflecting coverglass for multijunction cells in a terrestial high-concentrating photovoltaic system. 266-270. Paper presented at 27th European Photovoltaic Solar Energy Conference and Exhibition, Frankfurt, Germany. https://doi.org/10.4229/27thEUPVSEC2012-1AV.3.36
Micheli, L. ; Sarmah, N. ; Luo, X. ; Reddy, K.S. ; Mallick, T.K. / Infrared reflecting coverglass for multijunction cells in a terrestial high-concentrating photovoltaic system. Paper presented at 27th European Photovoltaic Solar Energy Conference and Exhibition, Frankfurt, Germany.5 p.
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Micheli, L, Sarmah, N, Luo, X, Reddy, KS & Mallick, TK 2012, 'Infrared reflecting coverglass for multijunction cells in a terrestial high-concentrating photovoltaic system' Paper presented at 27th European Photovoltaic Solar Energy Conference and Exhibition, Frankfurt, Germany, 24/09/12 - 28/09/12, pp. 266-270. https://doi.org/10.4229/27thEUPVSEC2012-1AV.3.36

Infrared reflecting coverglass for multijunction cells in a terrestial high-concentrating photovoltaic system. / Micheli, L.; Sarmah, N.; Luo, X.; Reddy, K.S.; Mallick, T.K.

2012. 266-270 Paper presented at 27th European Photovoltaic Solar Energy Conference and Exhibition, Frankfurt, Germany.

Research output: Contribution to conferencePaper

TY - CONF

T1 - Infrared reflecting coverglass for multijunction cells in a terrestial high-concentrating photovoltaic system

AU - Micheli, L.

AU - Sarmah, N.

AU - Luo, X.

AU - Reddy, K.S.

AU - Mallick, T.K.

PY - 2012

Y1 - 2012

N2 - Multijunction cells are composed of multiple layers of semiconductors, with different bandgaps. Among them, GaInP/GaAs/Ge cells are the most popular ones, due to their high performances [1]. These cells have higher efficiencies that silicon ones and should be really convenient in a concentrating photovoltaic plants. Photons are absorbed by a layer if their energy is equal or higher to the semiconductor bandgap. Otherwise they are transmitted to the lower semiconductor. All the photons with less energy than the lowest bandgap are converted into waste heat. They represent about the 5% of the total solar spectrum [2]. Moreover, the Germanium layer usually produces a higher current that the other subcells and even the excess current is converted into heat. Cooling is an important task in designing CPV: the higher the concentration the higher the temperature. Thus, a passive cooling effort can be obtained reducing the infrared radiation absorbed by the cell. An infrared reflecting layer placed on the top of the cell encapsulation should achieve this goal. This solution should reduce the quote of low-energy photons absorbed by the cell, decreasing both the sunlight directly converted into heat and the sunlight converted into excess current by the Germanium layer. Infrared reflecting coverglasses have been successfully tested on space applications. This research focuses on PMMA application for IR reflecting purposes in a terrestrial high CPV system.

AB - Multijunction cells are composed of multiple layers of semiconductors, with different bandgaps. Among them, GaInP/GaAs/Ge cells are the most popular ones, due to their high performances [1]. These cells have higher efficiencies that silicon ones and should be really convenient in a concentrating photovoltaic plants. Photons are absorbed by a layer if their energy is equal or higher to the semiconductor bandgap. Otherwise they are transmitted to the lower semiconductor. All the photons with less energy than the lowest bandgap are converted into waste heat. They represent about the 5% of the total solar spectrum [2]. Moreover, the Germanium layer usually produces a higher current that the other subcells and even the excess current is converted into heat. Cooling is an important task in designing CPV: the higher the concentration the higher the temperature. Thus, a passive cooling effort can be obtained reducing the infrared radiation absorbed by the cell. An infrared reflecting layer placed on the top of the cell encapsulation should achieve this goal. This solution should reduce the quote of low-energy photons absorbed by the cell, decreasing both the sunlight directly converted into heat and the sunlight converted into excess current by the Germanium layer. Infrared reflecting coverglasses have been successfully tested on space applications. This research focuses on PMMA application for IR reflecting purposes in a terrestrial high CPV system.

KW - multijunction solar cell

KW - concentrator cells

KW - solar cell efficiency

KW - semiconductors

UR - https://www.photovoltaic-conference.com/

U2 - 10.4229/27thEUPVSEC2012-1AV.3.36

DO - 10.4229/27thEUPVSEC2012-1AV.3.36

M3 - Paper

SP - 266

EP - 270

ER -

Micheli L, Sarmah N, Luo X, Reddy KS, Mallick TK. Infrared reflecting coverglass for multijunction cells in a terrestial high-concentrating photovoltaic system. 2012. Paper presented at 27th European Photovoltaic Solar Energy Conference and Exhibition, Frankfurt, Germany. https://doi.org/10.4229/27thEUPVSEC2012-1AV.3.36