Ultralong minority-carrier lifetime epitaxial GaAs by photon recycling

Ahrenkiel, R. K.; Dunlavy, D. J.; Keyes, B. M.; Vernon, S. M.; Dixon, T.M.; Tobin, S. P.; Miller, Kristi L.; Hayes, R.E.

doi:10.1063/1.101713

Cited by 87 publications

(37 citation statements)

References 15 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Using the reflectivity of the metal mirror, the thin-film cell can be designed to take advantage of the so-called photon recycling effect. This effect was already described in 1977 by Asbeck [49] and was experimentally confirmed by the very high photoluminescence lifetimes measured in GaAs layers cladded by AlGaAs [50]. Photons emitted through radiative recombination in the active layers are confined within the cell and likely to be re-absorbed.…”

Section: New Device Designssupporting

confidence: 51%

See 1 more Smart Citation

Thin-Film III–V Solar Cells Using Epitaxial Lift-Off

Bauhuis

Mulder

Schermer

2013

Springer Series in Materials Science

View full text Add to dashboard Cite

Epitaxial lift-off is used to create thin-film III-V solar cells without sacrificing the GaAs wafer. It is based on selective etching of an AlAs release layer between the wafer and the cell structure using an HF solution. The wafer can be reused for subsequent deposition runs thereby reducing the cost of the cells. The thin-film cell can be transferred to any new carrier, e.g. glass, plastic, silicon or metal foil. Although epitaxial lift-off was first demonstrated in 1978, it took until the 1990s to make significant progress in understanding the process and devising new ways to increase the etch rate. The first single-junction epitaxial lift-off cells were made in 1996. Thin-film cells offer new cell applications based on their flexibility, low weight and possibility to deposit the cell structure in reverse order. Today the world record for single-junction cells is held by a thin-film GaAs cell, who's performance is partly based on the increased photonrecycling factor in cells with a backcontact acting as a mirror. Also state of the art tandem and inverted metamorphic thin-film cells have been demonstrated.

show abstract

Section: New Device Designssupporting

confidence: 51%

“…the controlled spalling technology [61,62], are still in its infancy. In the last five years, companies like Alta Devices [63] and Microlink Devices [26,50,52,54] have developed a wafer-scale, epitaxial lift-off manufacturing process and are currently in pilot production. Activities in Europe are also initiated (tf2 devices).…”

Section: Future Perspectivesmentioning

confidence: 99%

Thin-Film III–V Solar Cells Using Epitaxial Lift-Off

Bauhuis

Mulder

Schermer

2013

Springer Series in Materials Science

View full text Add to dashboard Cite

show abstract

“…Since GaAs can be fabricated with very high purity and excellent surface passivation via III-V capping layers, we consider only Auger recombination as it is the sole intrinsic, unavoidable source of nonradiative recombination. 15,[21][22][23][24] With increased voltage from photon recycling, Auger recombination increases relative to radiative emission. Thus, as Figure 2b illustrates, the effect of Auger recombination is the greatest for narrow emission angles, and there is little benefit for emission angles below 1 6 .…”

Section: (2)mentioning

confidence: 99%

Highly efficient GaAs solar cells by limiting light emission angle

et al. 2013

View full text Add to dashboard Cite

In a conventional flat plate solar cell under direct sunlight, light is received from the solar disk, but is re-emitted isotropically. This isotropic emission corresponds to a significant entropy increase in the solar cell, with a corresponding drop in efficiency. Here, using a detailed balance model, we show that limiting the emission angle of a high-quality GaAs solar cell is a feasible route to achieving power conversion efficiencies above 38% with a single junction. The highest efficiencies are predicted for a thin, light trapping cell with an ideal back reflector, though the scheme is robust to a non-ideal back reflector. Comparison with a conventional planar cell geometry illustrates that limiting emission angle in a light trapping geometry not only allows for much thinner cells, but also for significantly higher overall efficiencies with an excellent rear reflector. Finally, we present ray-tracing and detailed balance analysis of two angular coupler designs, show that significant efficiency improvements are possible with these couplers, and demonstrate initial fabrication of one coupler design.

show abstract

“…The photon recycling factor affects the lifetime since the observed radiative lifetime is only a measure of the photons escaping the structure and photons emitted inside the absorber can easily be reabsorbed. 12,13 Re-absorption of photons in the structure extends the radiative lifetime by a factor / compared to the nominal radiative lifetime, which is s R ¼ 1/Bn 0 . With the modulated laser excitation power used in the OMR measurement technique, the excess carrier density, n e , is governed by the stationary and the modulated generation rates G 0 ($P 0 /(AdE ph )) and G 1 ($P 1 /(AdE ph )), respectively, as given by…”

mentioning

confidence: 99%