title: Solar cells. Electron-hole diffusion lengths > 175 μm in solution-grown CH3NH3PbI3 single crystals.
abstract: Long, balanced electron and hole diffusion lengths greater than 100 nanometers in the polycrystalline organolead trihalide compound CH3NH3PbI3 are critical for highly efficient perovskite solar cells. We found that the diffusion lengths in CH3NH3PbI3 single crystals grown by a solution-growth method can exceed 175 micrometers under 1 sun (100 mW cm(-2)) illumination and exceed 3 millimeters under weak light for both electrons and holes. The internal quantum efficiencies approach 100% in 3-millimeter-thick single-crystal perovskite solar cells under weak light. These long diffusion lengths result from greater carrier mobility, longer lifetime, and much smaller trap densities in the single crystals than in polycrystalline thin films. The long carrier diffusion lengths enabled the use of CH3NH3PbI3 in radiation sensing and energy harvesting through the gammavoltaic effect, with an efficiency of 3.9% measured with an intense cesium-137 source.
authors: Department of Mechanical and Materials Engineering, University of Nebraska, Lincoln, NE 68588, USA.
authors: Qingfeng
authors: Q
authors: Dong
authors: Department of Mechanical and Materials Engineering, University of Nebraska, Lincoln, NE 68588, USA.
authors: Yanjun
authors: Y
authors: Fang
authors: Department of Mechanical and Materials Engineering, University of Nebraska, Lincoln, NE 68588, USA.
authors: Yuchuan
authors: Y
authors: Shao
authors: Nuclear Engineering Program, Department of Mechanical and Aerospace Engineering, Ohio State University, Columbus, OH 43210, USA.
authors: Padhraic
authors: P
authors: Mulligan
authors: Nuclear Engineering Program, Department of Mechanical and Aerospace Engineering, Ohio State University, Columbus, OH 43210, USA.
authors: Jie
authors: J
authors: Qiu
authors: Nuclear Engineering Program, Department of Mechanical and Aerospace Engineering, Ohio State University, Columbus, OH 43210, USA.
authors: Lei
authors: L
authors: Cao
authors: Department of Mechanical and Materials Engineering, University of Nebraska, Lincoln, NE 68588, USA. jhuang2@unl.edu.
authors: Jinsong
authors: J
authors: Huang