Monolithic perovskite/silicon tandem solar cell with >29% efficiency by enhanced hole extraction

We report a monolithic perovskite/silicon tandem with a certified power conversion efficiency of 29.15%. The perovskite absorber, with a bandgap of 1.68 electron volts, remained phase-stable under illumination through a combination of fast hole extraction and minimized nonradiative recombination at the hole-selective interface. These features were made possible by a self-assembled, methyl-substituted carbazole monolayer as the hole-selective layer in the perovskite cell. The accelerated hole extraction was linked to a low ideality factor of 1.26 and single-junction fill factors of up to 84%, while enabling a tandem open-circuit voltage of as high as 1.92 volts. In air, without encapsulation, a tandem retained 95% of its initial efficiency after 300 hours of operation.

Source: ScienceNOW - December 10, 2020 Category: Science Authors: Al-Ashouri, A., Köhnen, E., Li, B., Magomedov, A., Hempel, H., Caprioglio, P., Marquez, J. A., Morales Vilches, A. B., Kasparavicius, E., Smith, J. A., Phung, N., Menzel, D., Grischek, M., Kegelmann, L., Skroblin, D., Gollwitzer, C., Malinauskas, Tags: Engineering, Materials Science r-articles Source Type: news