Chinese researchers develop perovskite-organic solar cell with record efficiency
Beijing (ANTARA) - Chinese researchers have recently developed a new perovskite-organic tandem solar cell that set a new world record with a steady-state photoelectric conversion efficiency of 28.04 per cent, according to a study published on Monday (13 July) in the journal Nature.
The solar cell, developed by the Institute of Chemistry of the Chinese Academy of Sciences (ICCAS), features a wide-bandgap perovskite top subcell that achieved the highest open-circuit voltage ever recorded for its type.
When precisely integrated with an organic bottom subcell, the tandem device’s power conversion efficiency in the laboratory peaked at 28.80 per cent, with a certified steady-state efficiency of 28.04 per cent. The cell also demonstrated outstanding operational stability, retaining 90 per cent of its initial efficiency after 625 hours of continuous illumination.
“This perovskite-organic tandem solar cell combines a lightweight design, mechanical flexibility, and high efficiency,” said Li Yongfang, an academician at the Chinese Academy of Sciences who led the research team.
“In addition to applications in buildings, transportation, and wearable electronics, its remarkable power-to-weight ratio makes it a promising candidate for future space missions, including satellites and space stations, where lighter and more efficient energy sources are essential,” Li explained.
Emerging photovoltaic technologies, particularly perovskite and organic solar cells, have advanced rapidly in recent years. Perovskite-organic tandem solar cells maximise the use of the solar spectrum, with the perovskite top layer capturing visible light while the organic bottom layer absorbs near-infrared light, yielding a theoretical efficiency far exceeding that of single-junction devices.
However, the top perovskite layer still faces challenges that are difficult to overcome. To absorb sufficient sunlight, the thin layer requires the simultaneous incorporation of iodine and bromine. The problem is that during fabrication or prolonged light exposure, iodide and bromide ions tend to separate — a phenomenon known as phase segregation — causing continuous voltage loss and performance degradation.
“This phase segregation has become the main bottleneck severely hindering the device’s operational stability and its commercial viability,” said Meng Lei, a researcher at the institute and a key member of the team.
To address this problem, the team added an additive molecule called TDB into the perovskite layer. During the early stages of perovskite film formation, TDB acts as a mediator, slowing the rapid aggregation of bromide ions and ensuring a homogeneous distribution of iodine and bromine from the outset.
Upon exposure to light, TDB transforms into a new molecular structure, TAB, which then attaches to the grain boundaries of the perovskite material. “This newly formed molecule effectively suppresses halide ion migration and phase segregation — a transformation from being light-intolerant to becoming light-adaptive,” said Meng.