Solar cells have always been renewable sources of energy as the sun’s energy seems to be in limitless supply, and much solar energy goes unused. Improvements in materials used to fabricate solar cells could greatly improve the utility of solar panels as the technology develops.
A photovoltaic cell converts sunlight through a crystalline structure, which adheres to a substrate material, to generate a differential. This produces voltage that is converted and inverted into usable power.
Perovskites are semiconductors with a unique crystalline structure that is ideal for solar cells and may be used as a substitute for the silicon that has been traditionally used. Silicon has posed limitations on the efficiency of the solar cells. These studies, however, demonstrate that perovskites could provide a significant boon to solar cells’ flexibility, durability and efficiency.
The perovskite crystals may be manufactured at room temperature, using much less energy than silicon. Thus, they are less expensive and their fabrication more sustainable. In addition, silicon is stiff and opaque, while perovskites are flexible and transparent. This opens many new possibilities for solar technology, as it may now be used to create solar panels that are flexible and continuous. For example, roofing tiles or roof coverings may be made that are not rigid at all and are durable enough to be placed on a roof without any notice and work quite efficiently.
The NREL research teams, who collaborated with the University of Colorado at Boulder and the University of Toledo, used a tin-lead perovskite cell that used two layers of perovskites and produced 25.5% efficiency.
The Princeton team was able to develop perovskite layers that are quite durable and long-lasting, surpassing previous limiting lifespans. They created perovskite solar cells with an expected life span of 30 years, which is suitable for commercial applications. This is a significant milestone in their use and development, as previously perovskites only last about 20 years.
In an interview in Sci-Tech Daily, one of the NREL researchers described this new material as “uniquely desirable: newly high efficiencies, an extraordinary ‘tunability’ that allows scientists to make highly specific applications, the ability to manufacture them locally with low energy inputs, and now a credible forecast of extended life coupled with a sophisticated aging process to test a wide array of designs.”