QuantaSol aims to produce concentrating solar cells that fit the individual requirements of its customers while maintaining the lowest possible cost of ownership. The company is designing cells specifically for terrestrial applications.
| Feature | Benefit | Technical Details |
|---|---|---|
| Tuneable Spectral Properties | Higher overall efficiency | The spectral response of an SB-QWPV cell can be tuned to maximise the conversion efficiency under a wide range of radiation spectra simply by varying composition and thickness of the III-V semiconductor nano-layers in the active region of the solar cell. Therefore:- a) SB-QWPVs can be engineered to maximise the efficiency of a single-junction cell (equal and systematically exceed the current world record) under the most typical solar spectra. b) SB-QWPVs provide a very effective solution to significantly enhance the efficiency of multi-junction cells over the current commercial solutions (like GaInP/GaAs or GaInP/GaAs/Ge) c) Photovoltaic cells for the conversion of a variety of narrow-band or monochromatic radiation sources can be designed with efficiencies as high as 50%-55% for use in applications such as Fibre Power. |
| No crystal defects | Best available structural stability, improved reliability and operating life. | The structural stability of an SB-QWPV cell is ensured by having oppositely stressed quantum wells and barriers which prevent any extended crystal defects to nucleate and propagate into the active region of the cell. Compared to a SB-QWPV, any bulk material having the same optimum light absorption-edge, cannot sustain the build-up of elastic energy due to the mismatch with respect to the crystal substrate. This means that plastic relaxation inevitably occurs somewhere in the heterostructures. Our studies show that no matter how low the number of extended defects like dislocations that can reach the active region, their negative impact on the dark current (opposite to the photocurrent) of the cell is inevitably significant. Moreover dislocations can accelerate the degradation of the device and therefore shorten its lifetime. |
| Photon Recycling | Higher conversion efficiency than competing cells. | At the typical operating point under solar concentration (>200x), SB-QWPVs are “radiatively limited†i.e. any lossy non-radiative carrier recombination becomes negligible. This effect, called “photon recyclingâ€, can be exploited by designing the cell in such a way that the radiation generated by the inevitable carrier recombination is partially recycled back into the active region of the device thus reducing the dark current (enhancing the open-circuit voltage). Tandem cells based on SB-QWPVs and designed to take full advantage of photon recycling (by means of radiative coupling between the sub-cells) are an innovative solution covered by one of our recent patent applications. |