One of the hurdles that prevent the mass adoption of solar power is the cost-to-efficiency ratio. Thin film solar cells, which are extremely affordable, are not efficient. Crystalline solar cells, which are highly efficient, are expensive. Researchers now say that twin-layered solar cells could be the solution to this problem.
What the Research Shows
Akhlesh Lakhtakia – a professor at Pennsylvania State University – says that using two layers of absorbent materials instead of just one layer will allow solar cells to absorb more light and convert it more efficiently.
Prof. Lakhtakia says that he used two different absorbent materials – copper indium gallium diselenide (CIGS) and copper zinc tin sulfur selenide (CZTSSe) – in his experiments to increase the efficiency of solar cells.
Individually, CIGS is about 20% efficient and CZTSSe is only about 11% efficient. When used together, however, their efficiency increases to 34%, which is quite remarkable to say the least.
Prof. Lakhtakia says that the combination of CIGS and CZTSSe works because these two materials are structurally very similar to each other. More importantly, they tend to absorb different frequencies of the spectrum, which is why when used together, they are able to absorb more sunlight than single-layered solar cells.
What It Means for the Solar Power Industry
Prof. Lakhtakia says that this is a significant breakthrough, as it can help us make solar cells more efficient without driving up their price tag to unaffordable levels.
Moreover, Prof. Lakhtakia also says that CIGS and CZTSSe might not be the only combination that can increase the efficiency of solar cells. He believes that other researchers might find other combinations that might be even better, which can make solar power more efficient and more affordable in the coming days.