Sharp's triple-layer solar cells stake claim for efficiency record

Electronics giant Sharp has laid claim to the world record for the highest solar cell conversion efficiency, announcing that its latest triple-junction compound cell has delivered an energy conversion rate of 35.8 per cent.

In a statement released last week, the company said its new cell design had broken the record for non-concentrator solar cells and had been independently verified by Japan's National Institute of Advanced Industrial Science and Technology.

The company said the photovoltaic cell used a compound design that allows it to use three photo-absorption layers to maximise the amount of solar energy the cells capture.

According to Sharp, previous triple-layer designs have been hampered by the use of germanium as the bottom layer of the cell, an element that generates a high level of current, which is wasted.

The company's researchers identified that a compound of indium gallium arsenide (InGaAs) would have a higher light utilisation efficiency, but manufacturing InGaAs with the regular atomic arrangement or crystallinity required for solar cells has proved difficult in the past.

However, Sharp said it has now successfully developed an undisclosed proprietary technology capable of producing high-quality InGaAs with high crystallinity and as a result, the conversion efficiency of its best-performing cells has risen from 31.5 per cent to 35.8 per cent.

The company said it would continue work to further increase efficiencies and commercialise the new triple-layer cells.