Non-wetting surface-driven high-aspect-ratio crystalline grain growth for efficient hybrid perovskite solar cells

Large-aspect-ratio grains are needed in polycrystalline thin-film solar cells for reduced charge recombination at grain boundaries; however, the grain size in organolead trihalide perovskite (OTP) films is generally limited by the film thickness. Here we report the growth of OTP grains with high average aspect ratio of 2.3-7.9 on a wide range of non-wetting hole transport layers (HTLs), which increase nucleus spacing by suppressing heterogeneous nucleation and facilitate grain boundary migration in grain growth by imposing less drag force. The reduced grain boundary area and improved crystallinity dramatically reduce the charge recombination in OTP thin films to the level in OTP single crystals. Combining the…

• NS
  National Science Foundation

  Awards: 1201384, DE-EE0006709, 1252623, ECCS-1201384, ECCS-1252623
• UD
  U.S. Department of Energy

  Awards: ECCS-1252623, ECCS-1201384, DE-EE0006709
• NP
  Nebraska Public Power District
• DO
  Division of Electrical, Communications and Cyber Systems

  Award: ECCS-1252623