Effects of luminescent coupling are observed in monolithic 5 V, five-junction GaAs phototransducers. Power conversion efficiency was measured at 61.6% 6 3% under the continuous, monochromatic illumination for which they were designed. Modeling shows that photon recycling can account for up to 350 mV of photovoltage in these devices. Drift-diffusion based simulations including a luminescent coupling term in the continuity equation show a broadening of the internal quantum efficiency curve which agrees well with experimental measurements. Luminescent coupling is shown to expand the spectral bandwidth of the phototransducer by a factor of at least 3.5 for devices with three or more junctions, even in cases where multiple absorption/emission events are required to transfer excess carriers into the limiting junction. We present a detailed description of the novel luminescent coupling modeling technique used to predict these performance enhancements. V C 2015 AIP Publishing LLC. [http://dx

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A novel method for incorporating the effects of luminescent coupling and photon recycling in numerical simulations of planar devices is described.The carrier generation is incorporated directly in the device simulator as an additional term in the continuity equation, so that no additional iterations are required. The method is applied to single-and four-junction solar cells containing ~1.0 eV dilute nitride material. We find that luminescent coupling increases the shortcircuit current ሺ ሻ of the 1-junction dilute nitride cell by 2.4% due to coupling with the Al 0.05 Ga 0.95 As filter. In the 4-junction design, there is significant photon recycling within the GaAs and GaInP sub-cells, providing a 60 mV increase in open-circuit voltage. There is a 1.9% relative increase in calculated efficiency to 44.4%.

READ THESE TERMS AND CONDITIONS CAREFULLY BEFORE USING THIS WEBSITE.http://nparc.cisti-icist.nrc-cnrc.gc.ca/eng/copyright Vous avez des questions? Nous pouvons vous aider. Pour communiquer directement avec un auteur, consultez la première page de la revue dans laquelle son article a été publié afin de trouver ses coordonnées. Si vous n'arrivez pas à les repérer, communiquez avec nous à PublicationsArchive-ArchivesPublications@nrc-cnrc.gc.ca. Questions? Contact the NRC Publications Archive team atPublicationsArchive-ArchivesPublications@nrc-cnrc.gc.ca. If you wish to email the authors directly, please see the first page of the publication for their contact information. NRC Publications Archive Archives des publications du CNRCThis publication could be one of several versions: author's original, accepted manuscript or the publisher's version. / La version de cette publication peut être l'une des suivantes : la version prépublication de l'auteur, la version acceptée du manuscrit ou la version de l'éditeur. NRC Publications Record / Notice d'Archives des publications de CNRC:http://nparc.cisti-icist.nrc-cnrc.gc.ca/eng/view/object/?id=b61b8697-879c-41ed-a72d-d183ad0b44f6 http://nparc.cisti-icist.nrc-cnrc.gc.ca/fra/voir/objet/?id=b61b8697-879c-41ed-a72d-d183ad0b44f6 Abstract: The down-shifting (DS) process is a purely optical approach used to improve the short-wavelength response of a solar cell by shifting high-energy photons to the visible range, which can be more efficiently absorbed by the solar cell. In addition to the DS effect, coupling a DS layer to the top surface of a solar cell results in a change in surface reflectance. The two effects are intermixed and therefore, usually reported as a single effect. Here we propose a procedure to decouple the two effects. Analytical equations are derived to decouple the two effects, that consider the experimentally measured quantum efficiency of the solar cell with and without the DS layer, in addition to transfer matrix simulations of the parasitic absorption in the device structure. In this work, an overall degradation of 0.46 mA/cm 2 is observed when adding a DS layer composed of silicon nanocrystals embedded in a quartz matrix to a silicon solar cell of 11% baseline efficiency. To fully understand the contribution from each effect, the surface reflectance and DS effects are decoupled and quantified using the described procedure. We observe an enhancement of 0.27 mA/cm 2 in short-circuit current density due to the DS effect, while the surface reflectance effect leads to a degradation of 0.73 mA/cm 2 in short-circuit current density.

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