17 July 2014 - Perovskite solar cells show tremendous promise in propelling solar power into the marketplace. The cells use a hole-transportation layer, which promotes the efficient movement of electrical current after exposure to sunlight. However, manufacturing the hole-transportation organic materials is very costly and lack long term stability. Publishing in Science, a team of scientists in China, led by Professor Hongwei Han in cooperation with Professor Michael Grätzel at EPFL, have developed a perovskite solar cell that does not use a hole-transporting layer, with 12.8% conversion efficiency and over 1000 hours stability under full sunlight in ambient temperature. The innovation can reduce the cost of perovskite cells, and firmly propel them into the marketplace.
Hybrid organic–inorganic methylammonium lead halide perovskites have attracted intense attention for thin-film photovoltaics, due to their large absorption coefficient, high charge carrier mobility and long diffusion length. However, these cells are also costly because of the hole-transportation layer, which demands high purity materials and complicated fabrication procedures. read more>>>