Monday, December 27, 2010

New Method Enhances Efficiency of Quantum Dots-Based Solar Cells

The Iranian researchers at Tabriz University introduced a novel method for increasing the efficiency of quantum dots-based solar cells.

Quantum dots (QDs)-based solar cells constituting the third generation of solar cells can directly convert the sunlight to electricity at 64% efficiency; however, per layer synthesis cost of their quantum dots is high.

Hossein Mola, physics specialist, conducted a series of researches aiming at optimizing the aforementioned cells and lowering their construction cost.

"It is possible to decrease the number of required layers by modeling QDs of different sizes targeting maximum sunlight absorption within multiple layers of active zone," he said to the INIC news service, noting that production cost per QD layer is high in QD solar cells.

Mola showed, by means of computational methods, that using QD layers of different sizes in solar cell active zone alongside the recombination time of carriers at QD affects the improvement of InxGa1-xN/GaN QD solar cells efficiency.

"The optimized number of QD layers is achieved under the assumption of two different carrier recombination times, through modeling method, and the current-voltage diagram for the two recombination times is obtained as well," he added.

The results imply that the maximum cell efficiency, yielded at the 7th QD layer, would increase from 16% to 28.3% as QD recombination time increases from 1 to 100 psec.

The details of the present study are available at Physica E, volume 42, pages 2353-2357, 2010.

Source: INIC

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