Proposed two-photon upconversion solar cell has theoretical efficiency of 63%

April 17, 2017
The two-photon process, already verified experimentally, could lead to real-world efficiencies of more than 50%.

As noted in Tech-On!, researchers at Kobe University (Kobe, Japan) have proposed a new solar-cell structure that uses two-photon upconversion to achieve a theoretical conversion efficiency higher than 50%.1 Experiments with a first prototype verified that the upconversion does indeed happen. The new structure enables absorption of sunlight's longer-wavelength spectral components, which have energies below the bandgap of the semiconductor and which normally pass through the photovoltaic cell and are lost.

The upper limit of the conversion efficiency of conventional single-junction solar cells is about 30%, meaning that most of the energy from incident sunlight is not absorbed by solar cells, either passing through the cells or turning into heat as surplus photon energy. The current world's highest solar cell efficiency is 46%, which was achieved with a quadruple-junction cell.

To realize the new solar-cell structure, the university used a hetero-interface consisting of two semiconductors, aluminum gallium arsenide (Al0.3Ga0.7As) and GaAs, having different bandgaps; the two-photon process happens at the boundary between the two semiconductors. The new structure generates a photoelectric current by converting two low-energy photons to one higher-energy photon that is absorbed by the cell. In theory, the conversion efficiency of the cell can reach up to 63%.

The new structure could become an ultrahigh-efficiency solar cell when improved by using optimal materials and refined structure. A conversion efficiency higher than 50% would lead to reductions in solar-cell installation areas of more than 50%, lowering both solar-cell and site construction costs.

Source: http://techon.nikkeibp.co.jp/atclen/news_en/15mk/041701281/

REFERENCE:

1. Shigeo Asahi et al., Nature Communications, 6 April 2017; doi:10.1038/ncomms14962

Sponsored Recommendations

How to Tune Servo Systems: Force Control

Oct. 23, 2024
Tuning the servo system to meet or exceed the performance specification can be a troubling task, join our webinar to learn to optimize performance.

Laser Machining: Dynamic Error Reduction via Galvo Compensation

Oct. 23, 2024
A common misconception is that high throughput implies higher speeds, but the real factor that impacts throughput is higher accelerations. Read more here!

Boost Productivity and Process Quality in High-Performance Laser Processing

Oct. 23, 2024
Read a discussion about developments in high-dynamic laser processing that improve process throughput and part quality.

Precision Automation Technologies that Minimize Laser Cut Hypotube Manufacturing Risk

Oct. 23, 2024
In this webinar, you will discover the precision automation technologies essential for manufacturing high-quality laser-cut hypotubes. Learn key processes, techniques, and best...

Voice your opinion!

To join the conversation, and become an exclusive member of Laser Focus World, create an account today!