1887
banner image
No data available.
Please log in to see this content.
You have no subscription access to this content.
No metrics data to plot.
The attempt to load metrics for this article has failed.
The attempt to plot a graph for these metrics has failed.
An extended model for upconversion in solar cells
Rent:
Rent this article for
USD
10.1063/1.3040692
/content/aip/journal/jap/104/11/10.1063/1.3040692
http://aip.metastore.ingenta.com/content/aip/journal/jap/104/11/10.1063/1.3040692

Figures

Image of FIG. 1.
FIG. 1.

C-RC system. The cell (medium 2) has the refractive index , and the rear upconverter (medium 3) has the refractive index . The solar cell and the upconverter are electronically isolated from each other. The subband-gap photons transmitted by the solar cell are partially upconverted into high-energy photons, which are subsequently absorbed in the solar cell. A reflector is located behind the upconverter. (a) The energy band diagram. An IL is located inside the converter’s band gap at energy above the VB edge. The widths of the valence and CBs are limited to ascertain photon selectivity. Dotted arrows symbolize the two-step generation of charge carrier pairs via the IL. The dashed arrow symbolizes the radiative recombination of a charge carrier pair via a band-to-band transition. , energy band gap; and , the bottom CB energy level and the top VB energy level, respectively, in the solar cell. (b) The equivalent electric circuit. The fictitious cells C2, C3, and C4 represent the band-to-band transitions and the two intermediate transitions, respectively. C1 represents the real solar cell.

Image of FIG. 2.
FIG. 2.

FC-C system. The upconverter (medium 2) has the refractive index , and the solar cell (medium 3) has the refractive index . (a) The energy band diagram. For details see the legend of Fig. 1(a). (b) The equivalent electric circuit. For details see the legend of Fig. 1(b).

Image of FIG. 3.
FIG. 3.

Dependence of the maximum solar energy conversion efficiency on cell band-gap for a solar cell operating alone, a C-RC configuration, and a FC-C configuration. Devices with and without AR coatings were considered. The following input values were used: unconcentrated solar radiation and similar refractive index and absorption factors for both solar cell and converter ( and ). (a) Ideal radiative recombination factors , (b) very good recombination factors , and (c) common present-day technology values for the recombination factors .

Image of FIG. 4.
FIG. 4.

Dependence of the maximum solar energy conversion efficiency on cell band-gap for two different quality solar cells, i.e., a high quality cell (Cgh: and ) and a standard low quality cell (Cp: and ). The graphs show the cells operating alone and included into a C-RC configuration or a FC-C configuration, respectively. Devices with and without AR coatings, respectively, were considered. The following input values were used: unconcentrated solar radiation and the same refractive index for both solar cell and converter . The converter absorption factors are always the same . (a) Cgh and converter with , (b) Cp and converter with , (c) Cgh and converter with , and (d) Cp and converter with .

Image of FIG. 5.
FIG. 5.

Dependence of the maximum solar energy conversion efficiency on the cell and converter refractive index ( and , respectively) for a C-RC system based on two different quality solar cells, i.e., a high quality cell (Cgh: and ) and a standard low quality cell (Cp: and ). Devices with AR coatings were considered. The following input values were used: unconcentrated solar radiation and cell band-gap . The converter absorption factors are always the same . (a) Cgh inside a C-RC system with , (b) Cp inside a C-RC system with , (c) Cgh inside a C-RC system with , and (d) Cp inside a C-RC system with .

Image of FIG. 6.
FIG. 6.

Dependence of the maximum solar energy conversion efficiency on cell band-gap for a high quality solar cell (Cgh; and ) operating alone and inside a C-RC configuration, respectively. Devices with AR coatings were considered. The following input values were used: similar refractive index and absorption factors for both solar cell and converter ( and ). Two values of the converter recombination factor were used: and 1. Concentration ratios: (a) , (b) , and (c) .

Tables

Generic image for table
Table I.

Factors entering Eqs. (7)–(10) of the present work and Eqs. (3)–(6) of Ref. 41 in the case of a C-RC system. This table refers only to geometrical factors and not to energy levels. Thus, here we treat cells C3 and C4 as identical (they both have the same refractive index). In the case of two materials with equal refractive indices, the étendue adopted in Ref. 41 for the radiation emitted from one material into the other is .

Generic image for table
Table II.

FC-C system. Factors entering Eqs. (11)–(14).

Loading

Article metrics loading...

/content/aip/journal/jap/104/11/10.1063/1.3040692
2008-12-15
2014-04-17
Loading

Full text loading...

This is a required field
Please enter a valid email address
752b84549af89a08dbdd7fdb8b9568b5 journal.articlezxybnytfddd
Scitation: An extended model for upconversion in solar cells
http://aip.metastore.ingenta.com/content/aip/journal/jap/104/11/10.1063/1.3040692
10.1063/1.3040692
SEARCH_EXPAND_ITEM