hough perovskite solar cells look to be well on the way to mass production, interest in the technology is still tempered by concerns about the stability of the material and its sensitivity to atmospheric conditions.
Scientists at the United States National Renewable Energy Laboratory (NREL) claim to have overcome one of those worries. By optimizing a cell’s chemical composition, they say they were able to suppress a mechanism known as light-induced phase segregation, which involves compounds in the solar device breaking down under constant exposure to light.
Most perovskite solar cells are fabricated with halides of iodine, bromine or chlorine. The NREL team, however, found a ‘triple perovskite’ incorporating all three materials offered several stability advantages and could also return the high conversion efficiency achieved by other perovskites.
The cells are described in the paper Triple-halide, wide-bandgap perovskites with suppressed phase-segregation for efficient tandems, published in Science. The group said its approach was unique because the researchers incorporated chlorine directly into the lattice at much higher amounts than in previous work. The scientists found the triple perovskite structure offered significant improvements in photocarrier lifetime and suppression of light-induced phase segregation, even at light intensities of up to 100 suns.