The only factor that can encourage utilities to rely more on solar energy is the efficiency of solar cells. While most traditional silicon solar cells try to reach close to the 25 percent mark on the efficiency scale, researchers have demonstrated that multi-junction solar cells coupled with solar concentrators can reach close to 50 percent. The current world record for triple-junction solar cells is 44 percent on the efficiency scale, but now collaboration between the Naval Research Laboratory, the Imperial College of London and MicroLink Devices has lead to the development of similar cells that can break the 50 percent efficiency barrier.
Multi-junction solar cells contain multiple layers of semiconducting material, each tuned to harvest a different spectrum of light, for more energy. When stacked one on top of the other, the cells can absorb more light and hence produce more energy. The key to the new design, according to Gizmag, is the identification of InAIAsSb alloys that enable the cells to achieve a maximum direct band gap of 1.8eV, much higher than commonly employed materials.
The researchers stated that the result of the research has produced a novel design that is, above all, realistically achievable, and can potentially break the 50 percent efficiency barrier under concentrated illumination.